Modular led lighting systems

ABSTRACT

In accordance with various embodiments, a modular lighting system features multiple light panels each having multiple light-emitting elements thereon, as well as connectors for electrically and mechanically interconnecting the light panels.

RELATED APPLICATIONS

This application claims the benefit of and priority to U.S. ProvisionalPatent Application No. 61/985,759, filed Apr. 29, 2014, and U.S.Provisional Patent Application No. 62/029,151, filed Jul. 25, 2014, theentire disclosure of each of which is hereby incorporated herein byreference.

FIELD OF THE INVENTION

In various embodiments, the present invention generally relates toelectronic devices, and more specifically to array-based electronicdevices.

BACKGROUND

Solid-state lighting is an attractive alternative to incandescent andfluorescent lighting systems for backlighting of translucent panels ormaterials and signs because of its relatively higher efficiency,robustness, and long life. A number of LED-based backlighting systemshave been used, but these generally suffer from one or moredeficiencies. It is often desirable to have the thickness of the panelor sign as small as possible, for example to fit within a restrictedspace, to provide a thin visual perspective, or to reduce cost. CurrentLED systems generally include LEDs that are operated at relatively highcurrent, resulting in very bright light sources that must be mixed anddiffused to provide even and low-glare illumination of the panel orsign. For systems having LEDs spaced several inches or more apart, thismay result in an undesirably large spacing between the LEDs and thediffuser. The diffuser reduces the efficiency, and as the LEDs becomebrighter, more diffusion, with concomitant decreasing efficiency, isrequired to achieve a homogeneous luminance across the panel or sign.Furthermore, such systems often require relatively large heat sinks orthermal management systems, which also take up space and may requiresuitable ventilation, for example passive ventilation or activeventilation such as fans, to prevent deleterious heat buildup. Theseissues typically lead to undesirably large, thick, and potentiallycomplicated lighting systems.

In addition, many applications for backlighting and illuminated panelsand signs require custom sizing to fit in a particular location. Systemsconsisting of relatively few high-brightness LEDs on rigid circuitboards or systems employing edge-lit panels may be difficult to usecost-effectively in a wide range of installations, e.g., installationsrequiring size customization while maintaining high illuminationuniformity and high efficiency.

Accordingly, there is a need for solutions that provide LED-basedlighting systems having a thin form factor with improved uniformity,high efficiency, and which are simple to install.

SUMMARY

Embodiments of the present invention relate to illumination systemsbased on flexible light sheets and that incorporate additionalfunctionality that enables various different mechanical mounting andelectrical and/or mechanical joining techniques. For example,illumination systems in accordance with embodiments of the inventionincorporate rigid or semi-rigid mounting frames that may also provideelectrical connectivity. In various embodiments, the illuminationsystems are modular and feature connection mechanisms (e.g., snapconnectors) that mechanically and electrically interconnect individuallight panels or light sheets together and/or to power-distributionsystems and/or to mounting rails.

Additional details of lighting systems in accordance with embodiments ofthe present invention appear within U.S. patent application Ser. No.13/799,807, filed Mar. 13, 2013 (the '807 application), and U.S. patentapplication Ser. No. 13/748,864, filed Jan. 24, 2013 (the '864application), the entire disclosure of each of which is incorporated byreference herein.

In an aspect, embodiments of the invention feature a lighting systemthat includes or consists essentially of a first light panel and asecond light panel. The first light panel includes or consistsessentially of a first substrate, first and second spaced-apart powerconductors disposed on the first substrate, a plurality of firstlight-emitting elements disposed on the first substrate and electricallyconnected to the first and second power conductors, a first snapconnector electrically connected to the first power conductor, and asecond snap connector electrically connected to the second powerconductor. The second light panel includes or consists essentially of asecond substrate, third and fourth spaced-apart power conductorsdisposed on the second substrate, a plurality of second light-emittingelements disposed on the second substrate and electrically connected tothe third and fourth power conductors, a third snap connectorelectrically connected to the third power conductor, and a fourth snapconnector electrically connected to the fourth power conductor. Thefirst snap connector is configured for connection to the third snapconnector, thereby electrically coupling the first power conductor tothe third power conductor. The second snap connector is configured forconnection to the fourth snap connector, thereby electrically couplingthe second power conductor to the fourth power conductor.

Embodiments of the invention may include one or more of the following inany of a variety of combinations. The third and/or fourth snapconnectors may be disposed on one or more tabs extending from the secondsubstrate. The third and/or fourth snap connectors may be disposed on afolded-over portion of one of the tabs extending from the secondsubstrate. The first light panel may include a fifth snap connectorelectrically connected to the first power conductor, and/or a sixth snapconnector electrically connected to the second power conductor. Thefifth and/or sixth snap connectors may be disposed on one or more tabsextending from the first substrate. The second light panel may include afifth snap connector and electrically connected to the third powerconductor, and/or a sixth snap connector and electrically connected tothe fourth power conductor. The fifth and/or sixth snap connectors maybe disposed on one or more tabs extending from the second substrate.

The lighting system may include a power distribution bus. The powerdistribution bus may include or consist essentially of first and secondpower distribution lines, a seventh snap connector electricallyconnected to the first power distribution line, and an eighth snapconnector electrically connected to the second power distribution line.The seventh snap connector may be configured for connection to the fifthsnap connector, thereby electrically coupling the third power conductorto the first power distribution line. The eighth snap connector may beconfigured for connection to the sixth snap connector, therebyelectrically coupling the fourth power conductor to the second powerdistribution line. The lighting system may include first and secondjumpers. The first jumper may include or consist essentially of a firstjumper connector configured for connection to the fifth snap connectorand a second jumper connector configured for connection to the seventhsnap connector, thereby electrically coupling the third power conductorto the first power distribution line. The second jumper may include orconsist essentially of a third jumper connector configured forconnection to the sixth snap connector and a fourth jumper connectorconfigured for connection to the eighth snap connector, therebyelectrically coupling the fourth power conductor to the second powerdistribution line. The first, second, third, and/or fourth snapconnectors may each include or consist essentially of at least a portionof a 9V battery connector. The first, second, third, and/or fourth snapconnectors may each include or consist essentially of a pin connector(e.g., an electrically conductive pin and/or an electrically conductivecap or ring shaped and sized to fit over the pin and make electricalcontact thereto).

When the first snap connector is connected to the third snap connectorand the second snap connector is connected to the fourth snap connector,over the first and second substrates, the first and secondlight-emitting elements may be spaced apart at a constant pitch, and thepitch may be maintained between the first and second substrates. Thefirst substrate may include a plurality of first conductive tracesthereon. The plurality of first light-emitting elements may be spacedapart and interconnected, via the plurality of first conductive traces,into one or more first light-emitting strings. Each first light-emittingstring may have (i) a first end electrically connected to the firstpower conductor and/or (ii) a second end electrically connected to thesecond power conductor. One or more first control elements may beconfigured to control current to one or more of the first light-emittingstrings. The one or more first control elements may be disposed on thefirst substrate and/or the second substrate. The one or more firstcontrol elements may each be electrically coupled to at least one firstlight-emitting string. The first substrate may be separable, via a cutspanning the first and second power conductors and not crossing a firstlight-emitting string, into two partial substrates each including orconsisting essentially of (i) one or more first light-emitting strings,and (ii) portions of the first and second power conductors configured tosupply power to and thereby illuminate the one or more firstlight-emitting strings of the partial substrate.

Along each first light-emitting string, a first pitch at which the firstlight-emitting elements are spaced may be substantially constant. Theone or more first light-emitting strings may include or consistessentially of a plurality of first light-emitting strings. Over thefirst substrate, the first light-emitting elements may be spaced apartat the first pitch, and the first pitch may be maintained between firstlight-emitting elements of different ones of the first light-emittingstrings. When the first snap connector is connected to the third snapconnector and the second snap connector is connected to the fourth snapconnector, over the first and second substrates, the first and secondlight-emitting elements may be spaced apart at the first pitch, and thefirst pitch may be maintained between the first and second substrates.The lighting system may include a third light panel and a fourth lightpanel. The third light panel may include or consist essentially of athird substrate, fifth and sixth spaced-apart power conductors disposedon the third substrate, a plurality of third light-emitting elementsdisposed on the third substrate and electrically connected to the fifthand sixth power conductors, a fifth snap connector electricallyconnected to the fifth power conductor, and a sixth snap connectorelectrically connected to the sixth power conductor. The fourth lightpanel may include or consist essentially of a fourth substrate, seventhand eighth spaced-apart power conductors disposed on the fourthsubstrate, a plurality of fourth light-emitting elements disposed on thefourth substrate and electrically connected to the seventh and eighthpower conductors, a seventh snap connector electrically connected to theseventh power conductor, and an eighth snap connector electricallyconnected to the eighth power conductor. The seventh snap connector maybe configured for connection to the fifth snap connector, therebyelectrically coupling the fifth power conductor to the eighth powerconductor. The eighth snap connector may be configured for connection tothe sixth snap connector, thereby electrically coupling the sixth powerconductor to the eighth power conductor. When (i) the first snapconnector is connected to the third snap connector, (ii) the second snapconnector is connected to the fourth snap connector, (iii) the fifthsnap connector is connected to the seventh snap connector, (iv) thesixth snap connector is connected to the eighth snap connector, (v) thefirst light panel is disposed adjacent to the third light panel, and(vi) the second light panel is disposed adjacent to the fourth lightpanel, over the first, second, third, and fourth substrates the first,second, third, and fourth light-emitting elements may be spaced apart ata constant pitch, and the pitch may be maintained among the first,second, third, and fourth substrates.

The first power conductor may be disposed proximate a first edge of thefirst substrate. The first edge may be folded to thereby increase aneffective width of the first power conductor. The second power conductormay be disposed proximate a second edge of the first substrate, thesecond edge being opposite the first edge. The second edge may be foldedto thereby increase an effective width of the second power conductor. Afirst frame element may be disposed proximate a first edge of the firstsubstrate. A second frame element may be disposed proximate a secondedge of the first substrate, the second edge being opposite the firstedge. The first power conductor may be disposed proximate the first edgeof the first substrate, and/or the second power conductor may bedisposed proximate the second edge of the first substrate. The firstframe element may include or consist essentially of a first electricallyconductive element. The first frame element may be configured toelectrically couple the first electrically conductive element to thefirst power conductor, thereby decreasing an effective electricalresistivity of the first power conductor. The second frame element mayinclude or consist essentially of a second electrically conductiveelement. The second frame element may be configured to electricallycouple the second electrically conductive element to the second powerconductor, thereby decreasing an effective electrical resistivity of thesecond power conductor.

A first frame element may be disposed at least partially on the firstsubstrate. The first frame element may be attached to the firstsubstrate by glue, adhesive, tape, conductive tape, conductive adhesive,anisotropic conductive adhesive, a magnet, a mechanical fastener, and/ora rivet. The first frame element may define therein at least onethrough-hole for mounting the lighting system to a mounting surface. Thefirst frame element may include or consist essentially of a firstportion, a second portion, and at least one hinge section coupling thefirst and second portions. The first substrate may be disposed betweenthe first portion and the second portion. The first frame element mayinclude or consist essentially of a first electrically conductiveelement. The first power conductor may include or consist essentially ofa plurality of electrically discontinuous sections. The firstelectrically conductive element may be configured to electricallyconnect at least two electrically discontinuous sections of the firstpower conductor. The first frame element may be flexible. The firstframe element may be positionable, whereby the first frame elementmaintains a deformed configuration in the absence of a deforming force.The first frame element may include or consist essentially of at leastone spacer. The at least one spacer may be fixed or adjustable. The atleast one spacer is configured to space the first light panel apart froma mounting surface. The lighting system may include an optic. The atleast one spacer may be configured to space the first light panel apartfrom the optic. The optic may include or consist essentially of a lens,a diffuser, a refractive optic, a reflective optic, a Fresnel optic, afabric, a translucent material panel, a graphic panel, and/or amembrane. The at least one spacer may have a reflectance greater than75%, or even greater than 85%, to a wavelength of light emitted by thefirst light-emitting elements.

The first light panel and/or the second light panel may have asubstantially square shape. The first light panel and/or the secondlight panel may have a substantially rectangular shape. The first lightpanel and/or the second light panel may have a substantially hexagonalshape. The first light panel and/or the second light panel may have asubstantially triangular shape. The first light panel and/or the secondlight panel may have a thickness in the range of 0.25 mm to 25 mm. Thefirst light-emitting elements and/or the second light-emitting elementsmay emit substantially white light. The first light-emitting elementsand/or the second light-emitting elements may include or consistessentially of light-emitting diodes. The first substrate and/or thesecond substrate may be flexible. The first and second substrates mayinclude or consist essentially of polyethylene terephthalate. The first,second, third, and fourth power conductors may include or consistessentially of copper and/or aluminum. An optic may be disposed over thefirst light panel and/or over the second light panel. The optic mayinclude or consist essentially of a lens, a diffuser, a refractiveoptic, a reflective optic, a Fresnel optic, a fabric, a translucentmaterial panel, a graphic panel, and/or a membrane. A collectivethickness of the first light panel and the optic may be less than 500mm, or even less than 100 mm. In another aspect, embodiments of theinvention feature a lighting system that includes or consistsessentially of a first light panel and a second light panel. The firstlight panel includes or consists essentially of a first substrate, firstand second spaced-apart power conductors disposed on the firstsubstrate, a plurality of first light-emitting elements disposed on thefirst substrate and electrically connected to the first and second powerconductors, a first frame element (i) disposed at least partially on thefirst substrate and (ii) including or consisting essentially of a firstelectrically conductive element, the first electrically conductiveelement being electrically connected to the first power conductor, and asecond frame element (i) disposed at least partially on the firstsubstrate and (ii) including or consisting essentially of a secondelectrically conductive element, the second electrically conductiveelement being electrically connected to the second power conductor. Thesecond light panel includes or consists essentially of a secondsubstrate, third and fourth spaced-apart power conductors disposed onthe second substrate, a plurality of second light-emitting elementsdisposed on the second substrate and electrically connected to the thirdand fourth power conductors, a third frame element (i) disposed at leastpartially on the second substrate and (ii) including or consistingessentially of a third electrically conductive element, the thirdelectrically conductive element being electrically connected to thethird power conductor, and a fourth frame element (i) disposed at leastpartially on the second substrate and (ii) including or consistingessentially of a fourth electrically conductive element, the fourthelectrically conductive element being electrically connected to thefourth power conductor. The first frame element is configured forconnection to the third frame element, thereby electrically coupling thefirst power conductor to the third power conductor. The second frameelement is configured for connection to the fourth frame element,thereby electrically coupling the second power conductor to the fourthpower conductor.

Embodiments of the invention may include one or more of the following inany of a variety of combinations. The first frame element may beconfigured for connection to the third frame element via a first snapconnector. The second frame element may be configured for connection tothe fourth frame element via a second snap connector. The first frameelement may be configured for connection to the third frame element viaa first magnet. The second frame element may be configured forconnection to the fourth frame element via a second magnet. The firstframe element may be configured for connection to the third frameelement via a first wire. The second frame element may be configured forconnection to the fourth frame element via a second wire. The firstsubstrate may include a plurality of first conductive traces thereon.The plurality of first light-emitting elements may be spaced apart andinterconnected, via the plurality of first conductive traces, into oneor more first light-emitting strings. Each first light-emitting stringmay have (i) a first end electrically connected to the first powerconductor and/or (ii) a second end electrically connected to the secondpower conductor. One or more first control elements may be configured tocontrol current to one or more of the first light-emitting strings. Theone or more first control elements may be disposed on the firstsubstrate and/or the second substrate. The one or more first controlelements may each be electrically coupled to at least one firstlight-emitting string. The first substrate may be separable, via a cutspanning the first and second power conductors and not crossing a firstlight-emitting string, into two partial substrates each including orconsisting essentially of (i) one or more first light-emitting strings,and (ii) portions of the first and second power conductors configured tosupply power to and thereby illuminate the one or more firstlight-emitting strings of the partial substrate.

Along each first light-emitting string, a first pitch at which the firstlight-emitting elements are spaced may be substantially constant. Theone or more first light-emitting strings may include or consistessentially of a plurality of first light-emitting strings. Over thefirst substrate, the first light-emitting elements may be spaced apartat the first pitch, and the first pitch may be maintained between firstlight-emitting elements of different ones of the first light-emittingstrings. When the first frame element is connected to the third frameelement and the second frame element is connected to the fourth frameelement, over the first and second substrates, the first and secondlight-emitting elements may be spaced apart at the first pitch, and thefirst pitch may be maintained between the first and second substrates.The lighting system may include a third light panel and a fourth lightpanel. The third light panel may include or consist essentially of athird substrate, fifth and sixth spaced-apart power conductors disposedon the third substrate, a plurality of third light-emitting elementsdisposed on the third substrate and electrically connected to the fifthand sixth power conductors, a fifth frame element (i) disposed at leastpartially on the third substrate and (ii) including or consistingessentially of a fifth electrically conductive element, the fifthelectrically conductive element being electrically connected to thefifth power conductor, and a sixth frame element (i) disposed at leastpartially on the third substrate and (ii) including or consistingessentially of a sixth electrically conductive element, the sixthelectrically conductive element being electrically connected to thesixth power conductor. The fourth light panel may include or consistessentially of a fourth substrate, seventh and eighth spaced-apart powerconductors disposed on the fourth substrate, a plurality of fourthlight-emitting elements disposed on the fourth substrate andelectrically connected to the seventh and eighth power conductors, aseventh frame element (i) disposed at least partially on the fourthsubstrate and (ii) including or consisting essentially of a seventhelectrically conductive element, the seventh electrically conductiveelement being electrically connected to the seventh power conductor, andan eighth frame element (i) disposed at least partially on the fourthsubstrate and (ii) including or consisting essentially of an eighthelectrically conductive element, the eighth electrically conductiveelement being electrically connected to the eighth power conductor. Theseventh frame element may be configured for connection to the fifthframe element, thereby electrically coupling the fifth power conductorto the eighth power conductor. The eighth frame element may beconfigured for connection to the sixth frame element, therebyelectrically coupling the sixth power conductor to the eighth powerconductor. When (i) the first frame element is connected to the thirdframe element, (ii) the second frame element is connected to the fourthframe element, (iii) the fifth frame element is connected to the seventhframe element, (iv) the sixth frame element is connected to the eighthframe element, (v) the first light panel is disposed adjacent to thethird light panel, and (vi) the second light panel is disposed adjacentto the fourth light panel, over the first, second, third, and fourthsubstrates the first, second, third, and fourth light-emitting elementsmay be spaced apart at a constant pitch, and the pitch may be maintainedamong the first, second, third, and fourth substrates.

The first power conductor may be disposed proximate a first edge of thefirst substrate. The first edge may be folded to thereby increase aneffective width of the first power conductor. The second power conductormay be disposed proximate a second edge of the first substrate, thesecond edge being opposite the first edge. The second edge may be foldedto thereby increase an effective width of the second power conductor.The first frame element may be disposed proximate a first edge of thefirst substrate, and/or the second frame element may be disposedproximate a second edge of the first substrate, the second edge beingopposite the first edge. The first power conductor may be disposedproximate the first edge of the first substrate, and/or the second powerconductor may be disposed proximate the second edge of the firstsubstrate. The first frame element may be attached to the firstsubstrate by glue, adhesive, tape, conductive tape, conductive adhesive,anisotropic conductive adhesive, a magnet, a mechanical fastener, and/ora rivet. The first frame element may define therein at least onethrough-hole configured for mounting the lighting system to a mountingsurface. The first frame element may include or consist essentially of afirst portion, a second portion, and at least one hinge section couplingthe first and second portions. The first substrate may be disposedbetween the first portion and the second portion. The first powerconductor may include or consist essentially of a plurality ofelectrically discontinuous sections, and the first electricallyconductive element may be configured to electrically connect at leasttwo electrically discontinuous sections of the first power conductor.

The first frame element and/or the second frame element may be flexible.The first frame element and/or the second frame element may bepositionable (i.e., maintaining a deformed configuration in the absenceof a deforming force). The first frame element may include or consistessentially of at least one spacer. The at least one spacer may be fixedor adjustable. The at least one spacer may be configured to space thefirst light panel apart from a mounting surface. The lighting system mayinclude an optic. The at least one spacer may be configured to space thefirst light panel apart from the optic. The optic may include or consistessentially of a lens, a diffuser, a refractive optic, a reflectiveoptic, a Fresnel optic, a fabric, a translucent material panel, agraphic panel, and/or a membrane. The at least one spacer may have areflectance greater than 75%, or even greater than 85%, to a wavelengthof light emitted by the first light-emitting elements. The first lightpanel and/or the second light panel may have a substantially squareshape. The first light panel and/or the second light panel may have asubstantially rectangular shape. The first light panel and/or the secondlight panel may have a substantially hexagonal shape. The first lightpanel and/or the second light panel may have a substantially triangularshape. The first light panel and/or the second light panel may have athickness in the range of 0.25 mm to 25 mm. The first light-emittingelements and/or the second light-emitting elements may emitsubstantially white light. The first light-emitting elements and/or thesecond light-emitting elements may include or consist essentially oflight-emitting diodes. The first substrate and/or the second substratemay be flexible. The first and second substrates may include or consistessentially of polyethylene terephthalate. The first, second, third, andfourth power conductors may include or consist essentially of copperand/or aluminum. An optic may be disposed over the first light paneland/or the second light panel. The optic may include or consistessentially of a lens, a diffuser, a refractive optic, a reflectiveoptic, a Fresnel optic, a fabric, a translucent material panel, agraphic panel, and/or a membrane. A collective thickness of the firstlight panel and the optic may be less than 500 mm, or even less than 100mm.

These and other objects, along with advantages and features of theinvention, will become more apparent through reference to the followingdescription, the accompanying drawings, and the claims. Furthermore, itis to be understood that the features of the various embodimentsdescribed herein are not mutually exclusive and can exist in variouscombinations and permutations. Reference throughout this specificationto “one example,” “an example,” “one embodiment,” or “an embodiment”means that a particular feature, structure, or characteristic describedin connection with the example is included in at least one example ofthe present technology. Thus, the occurrences of the phrases “in oneexample,” “in an example,” “one embodiment,” or “an embodiment” invarious places throughout this specification are not necessarily allreferring to the same example. Furthermore, the particular features,structures, routines, steps, or characteristics may be combined in anysuitable manner in one or more examples of the technology. As usedherein, the terms “about,” “approximately,” and “substantially” mean±10%, and in some embodiments, ±5%. The term “consists essentially of”means excluding other materials that contribute to function, unlessotherwise defined herein. Nonetheless, such other materials may bepresent, collectively or individually, in trace amounts.

Herein, two components such as light-emitting elements and/or opticalelements being “aligned” or “associated” with each other may refer tosuch components being mechanically and/or optically aligned. By“mechanically aligned” is meant coaxial or situated along a parallelaxis. By “optically aligned” is meant that at least some light (or otherelectromagnetic signal) emitted by or passing through one componentpasses through and/or is emitted by the other. As used herein, the terms“phosphor,” “wavelength-conversion material,” and “light-conversionmaterial” refer to any material that shifts the wavelength of lightstriking it and/or that is luminescent, fluorescent, and/orphosphorescent.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, like reference characters generally refer to the sameparts throughout the different views. Also, the drawings are notnecessarily to scale, emphasis instead generally being placed uponillustrating the principles of the invention. In the followingdescription, various embodiments of the present invention are describedwith reference to the following drawings, in which: p FIGS. 1A-1E areschematics of lighting panels in accordance with various embodiments ofthe invention;

FIG. 2A is a partial circuit diagram of a light sheet in accordance withvarious embodiments of the invention;

FIGS. 2B and 2C are partial schematics of light sheets in accordancewith various embodiments of the invention;

FIGS. 2D and 2E are partial circuit topologies of light sheets inaccordance with various embodiments of the invention;

FIG. 3 is a schematic of portions of a frame element in accordance withvarious embodiments of the invention;

FIGS. 4A-4E, 5A, and 5B are schematics of portions of a frame element inaccordance with various embodiments of the invention;

FIGS. 5C and 5D are schematics of a frame element in accordance withvarious embodiments of the invention;

FIGS. 6 and 7A-7C are schematics of illumination systems in accordancewith various embodiments of the invention;

FIGS. 7D-7F are schematics of tiled lighting panels in accordance withvarious embodiments of the invention;

FIG. 8A is a perspective view of a frame element incorporating aninsulation-displacement connector in accordance with various embodimentsof the invention;

FIG. 8B is a cross-sectional view of a portion of the frame element ofFIG. 8A;

FIG. 8C is a schematic illustration of a lighting system incorporatingfour light panels in accordance with various embodiments of theinvention;

FIGS. 9A and 9B are cross-sectional schematics of conductive elementsincorporated into frame elements in accordance with various embodimentsof the invention;

FIG. 10A is a plan-view schematic of joined light panels in accordancewith various embodiments of the invention;

FIG. 10B is a cross-sectional schematic of joined frame elements inaccordance with various embodiments of the invention;

FIG. 11A is a partial circuit diagram of a portion of a system inaccordance with various embodiments of the invention;

FIG. 11B is a plan-view schematic of a portion of a light sheet inaccordance with various embodiments of the invention;

FIG. 11C is a cross-sectional schematic of the light-sheet portion ofFIG. 11B;

FIG. 11D is a cross-sectional schematic of the interior of a frameelement in accordance with various embodiments of the invention;

FIGS. 12A-12D are cross-sectional schematics of frame elements inaccordance with various embodiments of the invention;

FIG. 13A is a schematic diagram of an illumination system featuring twoelectrically connected light sheets in accordance with variousembodiments of the invention;

FIG. 13B is a schematic cross-section of a clamping mechanism inaccordance with various embodiments of the invention;

FIG. 14 is a schematic diagram of a lighting system in accordance withvarious embodiments of the invention;

FIGS. 15A-15E are schematic diagrams of light panels in accordance withvarious embodiments of the invention;

FIG. 16 is a cross-sectional schematic of a portion of a light panel inaccordance with various embodiments of the invention;

FIGS. 17A-17C are schematic plan views of lighting systems in accordancewith various embodiments of the invention;

FIGS. 18A-18D are cross-sectional schematics of light panels or lightsheets incorporating electrical connectors in accordance with variousembodiments of the invention;

FIGS. 18E and 18F are cross-sectional schematics of light panels orlight sheets joined via electrical connectors in accordance with variousembodiments of the invention;

FIGS. 18G and 18H are views of electrical connectors in accordance withvarious embodiments of the invention;

FIG. 19A is a perspective view of a light panel or light sheetincorporating tabs and electrical connectors in accordance with variousembodiments of the invention;

FIGS. 19B-19D are magnified views of portions of light panels or lightsheets that are folded and feature electrical connectors in accordancewith various embodiments of the invention;

FIG. 19E is a perspective view of a light panel or light sheet havingfolded peripheral portions in accordance with various embodiments of theinvention;

FIG. 19F is a schematic comparison of power conductor width of foldedand unfolded light sheets or light panels in accordance with variousembodiments of the invention;

FIG. 19G is a schematic of a portion of a light sheet or light panelincorporating multiple folds in accordance with various embodiments ofthe invention;

FIG. 19H is a perspective view of a light panel or light sheet havingfolded peripheral portions in accordance with various embodiments of theinvention;

FIG. 19I is a schematic of a portion of a light sheet or light panelincorporating multiple folds in accordance with various embodiments ofthe invention;

FIGS. 19J, 19K, and 19L are schematics of power conductor configurationsin accordance with various embodiments of the invention;

FIGS. 20A and 20B are schematic plan views of light panels or lightsheets in accordance with various embodiments of the invention;

FIGS. 20C and 21A-21E are schematic plan views of lighting systemsincorporating electrically connected light panels or light sheets inaccordance with various embodiments of the invention; and

FIG. 21F is a schematic side view of an installed lighting system inaccordance with various embodiments of the invention.

DETAILED DESCRIPTION

FIG. 1A depicts an exemplary lighting panel 100 in accordance withembodiments of the present invention, although alternative systems withsimilar functionality are also within the scope of the invention. Invarious embodiments, lighting panel 100 includes or consists essentiallyof one or more flexible light sheets 110 and optionally one or moreflexible, positionable, semi-rigid, substantially rigid, or rigid frameelements 120. (FIG. 1A depicts two such frame elements, frame elements120, 120′.) Frame elements 120, 120′ may be disposed on all or portionsof one or more edges of light sheet 110. While FIG. 1A shows lightingpanel 100 having two frame elements 120, 120′ on opposite sides of lightsheet 110, this is not a limitation of the present invention, and inother embodiments lighting panel 100 may have frame elements 120 on oneside of light sheet 110, three sides of light sheet 110, or four sidesof light sheet 110 (i.e., one or more sides, or even all sides, of apolygonal light sheet 110). In various embodiments of the presentinvention lighting panel 100 may not include any frame elements. Invarious embodiments, one or more frame elements 120 may be disposed on anon-edge region of light sheet 110, e.g., a center portion within theedges defining light sheet 110, while in other embodiments one or moreportions of a frame element 120 may be disposed such that a portion ofthe frame element 120 extends beyond one or more edges of light sheet110.

While FIG. 1A shows frame elements 120 having a length about the same asthe length of the side of light sheet 110 on which they are formed, thisis not a limitation of the present invention, and in other embodimentsframe elements 120 may be longer or shorter than the associateddimension of light sheet 110. FIG. 1B shows an example of frame element120 having a length shorter than the associated dimension of light sheet110; however, in other embodiments frame element 120 may have a lengthlonger than the associated dimension of light sheet 110. While FIGS. 1Aand 1B show light sheet 110 as substantially square, this is not alimitation of the present invention, and in other embodiments lightsheet 110 may be rectangular, triangular, wedge or pie-section shaped,rhombohedral, hexagonal, circular, ellipsoidal, or have any arbitraryshape. FIGS. 1C, 1D, and 1E show examples of rectangular, triangular,and circular light sheets 110 respectively.

In various embodiments, light sheet 110 includes or consists essentiallyof an array of light-emitting elements (LEEs) electrically coupled byconductive traces formed on a flexible substrate, for example asdescribed in U.S. patent application Ser. No. 13/799,807, filed Mar. 13,2013 (the '807 application), or U.S. patent application Ser. No.13/970,027, filed Aug. 19, 2013 (the '027 application), the entiredisclosure of each of which is herein hereby incorporated by reference.

In various embodiments, various elements such as frame elements,substrates, or light sheets are “flexible” in the sense of being pliantin response to a force and resilient, i.e., tending to elasticallyresume an original or substantially original configuration upon removalof the force. Such elements may have a radius of curvature of about 50cm or less, or about 20 cm or less, or about 5 cm or less, or about 1 cmor less, or even about 0.5 cm or less. In various embodiments, flexibleelements may have a Young's Modulus less than about 50×10⁹ N/m², lessthan about 10×10⁹ N/m², or even less than about 5×10⁹ N/m². In variousembodiments, flexible elements may have a Shore A hardness value lessthan about 100; a Shore D hardness less than about 100; and/or aRockwell hardness less than about 150. In various embodiments, suchelements may permit folding and or creasing, for example folding of theelement over on itself (e.g., folding a portion of the element throughsubstantially 180°, such that the folded portion lays on and issubstantially parallel to the non-folded portion) without substantiallyimpairing the functionality of conductive traces on the substrate and/orthe functionality of the substrate. For example, in various embodiments,the functionality of the conductive trace may include a resistance orconductance value, a reliability metric, a mechanical metric, or thelike. In various embodiments, the functionality of the substrate mayinclude a resistance value, a reliability metric, a mechanical metric,or the like. In various embodiments, a folded or creased element mayhave a radius of curvature of less than 2 mm, or less than 1 mm or lessthan 0.05 mm. In various embodiments of the present invention, theelements may be folded or creased without damage or substantial damageto the elements, for example to the substrate and/or conductive trace.In various embodiments of the present invention, the elements may befolded or creased without changing or substantially changing theelectrical and/or mechanical and/or thermal and/or optical properties ofthe elements.

In various embodiments, various elements such as substrates, lightsheets, or frame elements may be positionable, in the sense that theyare pliant in response to a force, as with a flexible element, but uponremoval of the force, retain or substantially retain the deformed shape.In various embodiments such positionable characteristics may be achievedby plastic deformation of the element; however, this is not a limitationof the present invention, and in other embodiments the positionablecharacteristic may be achieved without substantial plastic deformationof the element. Such elements may have essentially any radius ofcurvature, but in particular may have a radius of curvature of about 50cm or less, or about 20 cm or less, or about 5 cm or less, or about 1 cmor less, or even about 0.5 cm or less.

In various embodiments, elements such as frame elements may be rigid orsubstantially rigid, in the sense that they are not pliant in responseto a force, i.e., tending to break or crack in response to a force. Invarious embodiments, various elements such as substrates, light sheets,or frame elements are semi-rigid, i.e., having a deformationcharacteristic between that of a flexible element and a rigid orsubstantially rigid element. Such elements may have a radius ofcurvature greater than about 50 cm.

FIG. 2A depicts an exemplary circuit topology, in accordance withembodiments of the present invention, which features conductive traces260, at least two power conductors 210, 220, multiple LEEs 230, andoptional control elements (CEs) 240. In various embodiments, LEEs 230may be configured in a regular periodic array, for example asubstantially square or rectangular array, where LEEs 230 are separatedby pitch (or “spacing”) 223 in the one direction (for example verticaldirection) by pitch 225 in a substantially orthogonal direction (forexample the horizontal direction; see FIG. 2C). In various embodiments,pitch 225 is the same as or substantially the same as pitch 223.

FIG. 2A shows two power conductors 210, 220, which may be used toprovide power to strings 250 of LEEs 230. Each string 250 may includetwo or more electrically coupled LEEs 230. LEEs 230 in string 250 may beelectrically coupled in series, as shown in FIG. 2A; however, this isnot a limitation of the present invention, and in other embodimentsother examples of electrical coupling may be utilized, for example LEEsin parallel or in any combination of series and parallel connections.FIG. 2A shows CE 240 in series with string 250; however, this is not alimitation of the present invention, and in other embodiments CE 240 mayhave different electrical coupling between power conductors 210, 220, ormay be absent altogether. For example, in various embodiments CE 240 maybe separately electrically coupled to power conductors 210, 220 and tothe LEE string 250, while in other embodiments each CE 240 may beelectrically coupled to two or more strings. The number of stringselectrically coupled to each CE 240 is not a limitation of the presentinvention. Combinations of structures described herein, as well as otherelectrical connections, all fall within the scope of the presentinvention. Power conductors 210, 220 may be used to provide power tostrings 250, for example AC power, DC power, or power modulated by anyother means. Each control element 240 may be, for example electricallyconnected to at least one light-emitting string 250 and configured toutilize power supplied from the power conductors 210, 220 to controlpower (e.g., supply a substantially constant current) to thelight-emitting string(s) 250 to which it is electrically connected.

Referring to FIGS. 2B and 2C that depict schematics of exemplary lightsheets 110, light sheet 110 features an array of LEEs 230 eachelectrically coupled between conductive traces 260, and power conductors210 and 220 providing power to conductive traces 260 and CEs 240, all ofwhich are disposed over a substrate 265. As utilized herein, a “wiringboard” refers to a substrate for LEEs with or without additionalelements such as conductive traces or CEs. A wiring board may also bereferred to as a light sheet or a circuit board. FIG. 2B shows anenlarged portion of an exemplary light sheet 110. In the exemplaryembodiment depicted in FIG. 2B, power conductors 210, 220 are spacedapart from each other and light-emitting strings (or simply “strings”)250 are connected in parallel across power conductors 210, 220. Invarious embodiments, for example as shown in FIG. 2B, strings 250 do notcross (i.e., intersect) each other. In other words, power conductors210, 220 are oriented in one direction and strings 250 are oriented suchthat they span power conductors 210, 220 in a different direction. Asshown in FIG. 2B, strings 250 may be substantially perpendicular topower conductors 210, 220. However, this is not a limitation of thepresent invention, and in other embodiments at least some segments(i.e., portions connecting two or more LEEs 230), or even the entirestrings 250, may define a line (not necessarily a straight line) that isnot perpendicular to power conductors 210, 220 yet is (at least for anentire string 250) not parallel to power conductors 210, 220. In otherembodiments strings 250 may intersect, for example one string 250splitting into two or more strings 250, or two or more strings 250joining to form a reduced number of strings 250. In various embodiments,conductive traces 260 may cross over each other without beingelectrically coupled to each other, and in various embodiments, strings250 may cross over or under each other without being electricallycoupled to each other. In various embodiments, all or a portion of oneor more strings 250 may extend beyond the area disposed between thepower conductors 210, 220. Various examples of string geometries andconformations utilized in embodiments of the present invention aredetailed in the '807 and '027 applications.

As shown in FIGS. 2B and 2C, LEEs 230 may be positioned across substrate265 in a regular periodic array, although this is not a limitation ofthe present invention, and in other embodiments LEEs 230 may occupy anypositions on light sheet 110. Power conductors 210 and 220 provide powerto each LEE string, for example the string 250 encircled by the dashedline in FIG. 2B. Each LEE string 250 typically includes multipleconductive traces 260 that interconnect multiple LEEs 230, as well asone or more CEs 240, which in FIG. 2B is in series with LEEs 230. String250 shown in FIG. 2B is a folded string, i.e., a string that has threesegments electrically coupled in series but positioned as three adjacentsegments. A string segment is a portion of a string spanning all or aportion of the region between power conductors (e.g., power conductors210 and 220 in FIG. 2B). In light sheet 110, some string segments mayinclude LEEs 230 and others may not. However, in other embodiments, thedistribution and position of LEEs 230 along conductive elements 260 andstring segments may be different. In various embodiments, a string 250may be a straight string, i.e., a string with no folds, as shown in FIG.2C. (The example shown in FIG. 2C does not include CEs 240.) In astraight string, one end of string 250 is electrically coupled to powerconductor 210, while the other end of string 250 is electrically coupledto power conductor 220 with no turns or corners therebetween. As will bediscussed, the number of segments in a string 250 is not a limitation ofthe present invention. Various examples of straight and folded stringsutilized in embodiments of the present invention are detailed in the'807 and '027 applications.

FIGS. 2A and 2B illustrate three aspects of various embodiments inaccordance with embodiments of the present invention. The first is themultiple strings 250 that are powered by the set of power conductors210, 220. The second is the positional relationship between thelocations of LEEs 230 and CE 240, which is disposed between theconductive traces 260 and between power conductors 210,220. The third isthe inclusion of a CE 240 in each string of series-connected LEEs 230.Combinations of these three aspects enable light sheet 110 to beeconomically manufactured in very long lengths, for example in aroll-to-roll process, and cut to specified lengths, forming lightsheets, while maintaining the ability to tile, or place light sheetsadjacent to each other (e.g., in the length direction), with no orsubstantially no change in pitch between LEEs 230 or in the opticalcharacteristics across the joint between two adjacent light sheets, asdiscussed in more detail in the '807 and '027 applications.

In an exemplary embodiment, CE 240 is configured to regulate the currentor maintain a constant or substantially constant current through LEEs230 of string 250. For example, in various embodiments, a constant orsubstantially constant voltage may be applied to power conductors 210,220, which may, under certain circumstances may have some variation, orthe sum of the forward voltages of LEEs 230 in different strings may besomewhat different, for example as a result of LEE manufacturingtolerances, or the component and/or operational values of the element(s)within CE 240 may vary, for example as a result of manufacturingtolerances or changes in operating temperature, and CE 240 acts tomaintain the current through LEEs 230 substantially constant in the faceof these variations. In other words, in various embodiments the input tothe light sheet is a constant voltage that is applied to powerconductors 210, 220, and CEs 240 convert the constant voltage to aconstant or substantially constant current through LEEs 230. As will bedescribed herein, the design of CE 240 may be varied to providedifferent levels of control or variation of the current through LEEs230. In various embodiments, CEs 240 may control the current throughLEEs 230 to be substantially constant with a variation of less thanabout ±25%. In various embodiments, CEs 240 may control the currentthrough LEEs 230 to be substantially constant with a variation of lessthan about ±15%. In various embodiments, CEs 240 may control the currentthrough LEEs 230 to be substantially constant with a variation of lessthan about ±10%. In various embodiments, CEs 240 may control the currentthrough LEEs 230 to be substantially constant with a variation of lessthan about ±5%.

In various embodiments, as described herein, CEs 240 may, in response toa control signal, act to maintain a constant or substantially constantcurrent through LEEs 230 until instructed to change to a differentconstant or substantially constant current, for example by an externalcontrol signal. In various embodiments, as described herein, all CEs 240on a sheet may act in concert, that is maintain or change the currentthrough all associated LEEs 230; however, this is not a limitation ofthe present invention, and in other embodiments one or more CEs 240 maybe individually controlled and/or energized.

While FIG. 2A shows one exemplary circuit topology, this is not alimitation of the present invention, and in other embodiments othercircuit topologies may be utilized. For example, in various embodimentsthe circuit may not include any CEs 240. In various embodiments of thepresent invention, the electrical topology may include one or morecross-connecting elements, for example which may electrically coupleconductive elements in in separate strings, for example as described inU.S. patent application Ser. No. 13/378,880, filed on Dec. 16, 2011, andU.S. patent application Ser. No. 13/183,684, filed on Jul. 15, 2011, theentirety of each of which is incorporated by reference herein. FIGS. 2Dand 2E show two examples of such a cross-connection topology. In thecircuit shown in FIG. 2D, each LEE 230 is cross-connected with adjacentLEEs 230, while in FIG. 2E, only some of LEEs 230 are cross-connectedwith adjacent LEEs 230.

In various embodiments of the present invention, frame elements 120provide a rigid or semi-rigid support for light sheet 110. In variousembodiments, a frame element 120 may include or consist essentially of aplastic material, for example acrylic, acrylonitrile butadiene styrene(ABS), polyethylene, thermoplastic polyurethane (TPU), or the like. Invarious embodiments, frame element 120 may include or consistessentially of one or more metals, such as aluminum, copper, or thelike, or silicone, wood or other materials. In various embodiments,frame element 120 may include or consist essentially of a combination ofmaterials.

In various embodiments of the present invention, frame elements 120provide a flexible support for light sheet 110. In various embodimentsof the present invention, frame elements 120 provide a positionablesupport for light sheet 110.

In various embodiments, light sheet 110 has one or more openings (or“holes”), for example along the edge of light sheet 110, that mate toframe element 120, and frame element 120 has one or more correspondinglocating pins over which the holes are positioned, to provide accurateand repeatable positioning of light sheet 110 in frame element 120. FIG.3 shows a schematic of one embodiment that features locating pins 310 onframe element 120 and locating holes 320 in light sheet 110. FIG. 3shows two light sheets, 110 and 110′. Light sheet 110 is positionedabove frame element 120 while light sheet 110′ is positioned on frameelement 120 such that locator pin 310 is at least partially insertedinto locating hole 320. FIG. 3 shows one additional aspect of variousembodiments of the present invention, in which a frame element 120 maybe used to couple two or more light sheets 110 together into a singlelighting system. While the structures shown in FIGS. 3 and 4A-4C usepins and holes to align one or more light sheets 110 to one or moreframe elements 120, this is not a limitation of the present invention,and in other embodiments other techniques and/or structures may beutilized to align and/or hold light sheet 110 in frame element 120. Forexample, light sheet 110 may be aligned to frame element 120 usingalignment marks on light sheet 110 and/or frame element 120. In variousembodiments, light sheet 110 may be attached or fastened to frameelement 120 by other means, for example screws, nuts and bolts, tape,adhesive, glue, external clamps, magnets, heat stakes, or the like. Forexample, FIG. 4D shows a two-piece frame element 120 fastened to lightsheet 110 using a clamp or spring clamp 450. FIG. 4E shows anotherexample in which frame element 120 (having a hinge 430) is fastened tolight sheet 110 using an adhesive 460. In various embodiments, adhesive460 may include or consist essentially of glue, tape, double-sided tape,or the like. The method of attaching light sheet 110 to frame element120 is not a limitation of the present invention.

In various embodiments, frame element 120 has one or more hinges, suchthat the frame element 120 may be folded over and clamped to light sheet110. In various embodiments, the locating pins in frame element 120 mayact as a fastener that keeps (or helps keep) frame element 120 closedaround light sheet 110. FIGS. 4A and 4B show a schematic of oneembodiment of the present invention. FIG. 4A shows an unfolded frameelement 120 that includes or consists essentially of a hinge 430, alocating pin 410 (that is composed of two or more protrusions), and alocating hole 420. In the depicted embodiment, locating pin 410 isdesigned to be compressed before being inserted through locating hole420 and then to spring open to lock frame element 120 in the folded orclosed position, as shown in FIG. 4B. In various embodiments, locatingpin 410 may include or consist essentially of a snap hook instead of acompression element, as shown in FIG. 5A (unfolded, or “open,”conformation) and 5B (folded, or “closed,” conformation). FIG. 4B showslight sheet 110 clamped into a folded frame element 120, where locatingpin 410 has been inserted through locating hole 320 in light sheet 110and through locating hole 420 in frame element 120. In variousembodiments, frame element 120 and/or light sheet 110 may include holesthat may be used for mounting frame element 120. FIG. 4C shows oneexample of such an embodiment, in which the light panel 100 has mountinghole 440 that goes through light sheet 110 and frame element 120. Asdescribed herein, mounting hole 440 includes or consists essentially ofmounting hole 441 in frame element 120 and mounting hole 442 in lightsheet 110. FIGS. 5C and 5D show schematic views of one embodiment offrame element 120 in the open and closed positions, respectively.

As described herein, light panel 100 may be designed to be cut tolength, for example between strings 250, such that at least one andoptionally both sections are operable after separation. In variousembodiments, light panel 100 includes locating pins 310 and/or locatingpins and holes 410, 420 and/or mounting holes 441, 442, to permitlocating, clamping, and/or mounting of light panel 100 after light panel100 (including or consisting substantially of one or more light sheets110 and one or more frame elements 120) has been cut or separated intoone or more portions. FIG. 6 shows a schematic of one embodiment showingtwo strings 250 and 250′ and a separation or cut region 620 on frameelement 120 and a separation or cut region 610 on light sheet 110. Asshown, the section including string 250 also includes mounting hole 440and locating pin/fastener 410, and the section including string 250′also includes mounting hole 440′ and locating pin/fastener 410′. Iflighting panel 100 is separated along cur regions 620 and 610, eachsection has its own mounting hole and locating pin/fastener. In variousembodiments, frame element 120 and light sheet 110 are designed tofacilitate separation of lighting panel 100, for example byincorporating identified separation lines or regions on frame element120 and/or light sheet 110. For example, in various embodimentsseparation line 610 may be formed on light sheet 110 by printing, or bya pattern in one or more conductive elements 260 and/or one or bothpower conductors 210, 220. In various embodiments, cut region 610 may befree of or substantially free of conductive elements 265. In variousembodiments, light sheet 110 may include a coating over all or portionsof substrate 265, power conductors 210, 220 and conductive elements 265and separation line 610 may be formed in the coating material, or by theabsence of the coating material in separation region 610. In variousembodiments, separation line 620 on frame element 120 may include orconsist essentially of markings on frame element 120, for example thatare formed in frame element 120 or printed on frame element 120. Invarious embodiments, separation line 620 may include or consistessentially of a region engineered to separate more easily than adjacentregions of frame element 120, for example by having a reduced thicknesscompared to adjacent regions of frame 120 and/or perforations definedtherein. In various embodiments, light panel 100 may be separated bycutting through frame element 120 in region 620 and light sheet 110 inregion 610, for example with a scissors or knife or other cuttingimplement. The means of separation of light panel 100 is not alimitation of the present invention.

In various embodiments, light panel 100 may be mounted (e.g., to amounting surface such as a wall, a ceiling, or a fixture), for exampleusing screws or nails or other fasteners that may be inserted throughmounting holes 440; however, this is not a limitation of the presentinvention, and in other embodiments light panel 100 may be mounted byother means, for example staples, tape, double-sided tape, magnets, ahook-and-loop fastener such as Velcro, or the like. In variousembodiments, frame element 120 may include or incorporate mountingelements, for example double-sided tape or barbed pins that may be usedto mount light panel 100 to a mounting surface.

In various embodiments, frame element 120 may be designed to have awidth less than one-half of the pitch between LEEs 230 in the directionbetween frame elements 120 of adjacent light panels 100, such that iftwo light panels 100 are positioned next to each other, the pitchbetween nearest neighbor LEEs 230 on adjacent light panels 100 may bethe same or substantially the same as the pitch between nearest neighborLEEs 230 on each light panel 100. FIG. 7A shows a schematic of oneexample of this embodiment, depicting two light panels 100 and 100′,each featuring frame elements 120 and light sheets 110. As shown, apitch 223 between LEEs 230 in the direction between frame elements isthe same on light panels 100 and 100′ as it is between LEEs 230 onadjacent light sheets 110 and separated by frame elements 120. Forexample, in various embodiments LEE pitch 223 may be about 30 mm andframe element 120 may have a width in the range of about 5 mm to about14 mm. In various embodiments, the width 710 of frame element 120 may beless than about 0.95×(pitch 223/2). In various embodiments, LEE pitch223 may be about 20 mm and frame width 710 may be in the range of about3 mm to about 9 mm.

FIG. 7B shows an example featuring four light panels 100 (one panel isencircled in a heavy dashed line), each panel 100 including two frameelements 120 on opposite sides of light sheet 110. As shown, pitch 223is the same on one sheet as it is across frame elements 120 on adjacentsheets. In this example LEE pitch 223 is about 30 mm and frame width 710is about 10 mm.

FIG. 7B shows an additional feature that may be incorporated in variousembodiments of the present invention, identified as connector 720.Connector 720 may be utilized to join together two frame elements 120.In various embodiments, connector 720 may be designed such that pitch225 is the same between nearest-neighbor LEEs 230 on adjacent lightsheets 110 as it is on a single light sheet 110. In various embodiments,connector 720 may include or consist essentially of a portion of frameelement 120 that extends beyond the length of light sheet 110 andincludes a mechanism for attaching to an adjacent frame element 120. Forexample in various embodiments, as shown in FIG. 7C, connector 720′ mayinclude a locating hole 730′ in frame element 120′ and that fits over alocating pin 740 on an adjacent frame element 120. In variousembodiments, there may be a corresponding section 720 on the other endof frame element 120 (i.e., away from connector 720′, not shown in FIG.7C). Locating hole 730′ and locating pin 740 are preferably positionedsuch that pitch 225 between LEEs in the direction along frame elements120, 120′ is the same between light panels 100 as on an individual lightpanel 100, irrespective of the interface between the light panels 100.In various embodiments, locating pin 740 may also be used to positionlight sheet 110, similar to the approach discussed in reference to FIG.3. In various embodiments, connector 720 may include a conventionalelectrical connector, such as a pin and jack system, where adjacentlight sheets 120 are electrically coupled through the electricalconnector. For example, a frame element may feature a connectorelectrically coupled to a power conductor on the light sheet, and theconnector may be electrically coupled to a corresponding connector on anadjacent frame element. In various embodiments, the electricalconnectors (or electrical portions of the connector) may mate directly,while in other embodiments a jumper wire may be used to electricallycouple the two connectors. In various embodiments, such a system may beemployed to electrically couple two or more light panels that are spacedapart from each other.

In various embodiments, the system shown in FIG. 7B includes frameelements 120 that, when attached to light sheet 110, have a width 710 ofabout 10 mm. In this example light sheet 110 has a square shape with aside length of about 300 mm. LEEs 230 have a pitch 223 of about 33 mmand a pitch 225 of about 30 mm. In this example connector 720 has alength beyond light sheet 110 in the range of about 5 mm to about 30 mm.These dimensions are exemplary and not limitations of the presentinvention.

The ability to tile light panels 100 in multiple directions provides asystem that may be utilized to make arbitrarily large assemblies havinguniform illuminance with no relatively darker areas in the joint regionsbetween adjacent panels.

While the systems described in reference to FIGS. 6 and 7A-7C pertain torectilinear light panels, this is not a limitation of the presentinvention, and in other embodiments other light panel shapes may beused. For example FIG. 7D shows a light panel system incorporatingtriangular light panels, FIG. 7E shows a system incorporatingdiamond-shaped light panels, and FIG. 7F shows a system incorporatinghexagonal light panels. The shapes depicted in FIGS. 7D-7F are meant tobe exemplary and are not limitations of the present invention.

In various embodiments, frame elements 120 provide support for lightsheets 110 and a means for providing electrical connections to lightsheet 110, for example to provide power to power conductors 210, 220. Invarious embodiments, frame elements 120 enable electrical coupling ofone or more control signals, for example to dim or change the intensityof one or more LEEs 230 on light sheet 110, or to change the color oflight emitted by LEEs 230, to light sheet 110.

FIG. 8A shows one embodiment of a frame element 120 that incorporates aninsulation-displacement connector (IDC) 810 that is electrically coupledto one of power conductors 210, 220 on light sheet 110. (As utilizedherein, an IDC is an electrical connector designed to be connected tothe conductor(s) of an insulated wire or cable by a connection processthat forces a selectively sharpened blade or blades (or other cutting orpiercing element) through the insulation, bypassing the need to stripthe wire of insulation before connecting.) Note that FIG. 8A shows twoadjacent light panels. IDC 810 is formed or disposed into a hole inframe element 120, permitting access to it when light sheet 110 isattached to frame element 120. A wire 830, preferably an insulated wire,is inserted in IDC 810, which then provides electrical connection topower conductors 210, 220 on light sheet 110. FIG. 8B shows across-sectional schematic of such a structure, including a bottomportion 120B of the frame element, a top portion 120T of the frameelement, and a hole 820 through which IDC 810 is inserted. IDC 810 iselectrically coupled to power conductor 210, for example using solder,conductive adhesive, anisotropic conductive adhesive, or the like. Powerconductor 210 is disposed on substrate 265. Referring back to FIG. 8A,after frame 120 is attached to light sheet 110, wire 830 is insertedinto IDC 810 to electrically couple wire 830 to the underlyingconductive element (not shown in FIG. 8A, and in FIG. 8B is exemplifiedby power conductor 210). Optional cap 840 may be used to aid ininsertion of wire 830 into IDC 810 and/or to provide a protective coverover IDC 810. Optional guide elements 850 may be utilized to hold wire830 into place on frame element 120. FIG. 8A also shows mounting holes440. In the depicted embodiment, frame element 120 is installedsubstantially parallel to and over power conductors 210, 220 on lightsheet 110.

FIG. 8C shows a schematic of a lighting system incorporating four lightpanels 100. The lighting system is powered by a driver 860, which iselectrically coupled to light panels 100 through wires 830 and 830′. Invarious embodiments, this and similar arrangements permit the assemblyof very large lighting systems without the need for the power conductors210, 220 to have sufficient conductivity to support the entire assembly,because wires 830, 830′ have relatively larger conductivity and providea low resistance shunt to power conductors 210, 220. In variousembodiments, for example where it may be desirable to separate the lightpanel into smaller sections (e.g., in reference to FIG. 6), several IDCs810 may be incorporated on light sheet 110 to permit separation into twoor more portions, each of which has an IDC 810. In various embodiments,one or more electrical conductors may be incorporated into frame element120. For example, in various embodiments, frame element 120 features aconductive element 910 that is attached to or embedded or partiallyembedded into frame element 120, as shown in FIG. 9A. Frame element 120is clamped onto light sheet 110, forming an electrical and mechanicalconnection between conductive element 910 and power conductor 210. Invarious embodiments, conductive element 910 may be mounted on a surfaceof frame element 120, as shown in FIG. 9B. In various embodiments,conductive element 910 includes or consists essentially of one or moreelectrically conductive materials such as metals such as aluminum,copper, silver, gold, or the like. In various embodiments, conductiveelement 910 may include or consist essentially of a metal foil or metalstrip. In various embodiments, conductive element 910 includes anelectrically conductive tape, for example one that is conductive in boththe lateral and z (i.e., through-thickness) directions, such that alow-resistance pathway forms between power conductor 210 and conductiveelement 910 and conductive element 910 forms a low-resistance pathway inparallel with power conductor 210. In various embodiments, conductiveelement 910 includes or consists essentially of a combination ofmaterials, for example a metal layer over which is disposed a conductiveadhesive or a conductive tape. In various embodiments, IDC 810 may bereplaced by a pin or a barbed pin that mates with a correspondingconnector or pierces a conductive element 910 mounted in frame element120.

Electrical connection between adjacent light panels 100 and betweenlight panels 100 and one or more power supplies or drivers may be formedthrough frame elements 120. In various embodiments, magnets of theappropriate polarity may be mounted or formed within or at the ends offrame elements 120, such that each frame may be mechanically andelectrically connected through the magnets, for example as shown in FIG.10A. In FIG. 10A, the opposing faces of magnets 1010 and 1020 haveopposite polarities, so that the light panels may only be connected inone way. In various embodiments, this prevents incorrect connection ofmultiple light panels 100.

In various embodiments, frame element 120 may include one or moreconnectors or mechanisms for electrical coupling. In variousembodiments, conductive elements such as conductive elements 910, asshown in FIGS. 9A and 9B, may be used to electrically couple two frames.FIG. 10B shows one example featuring the joining of frames 120 and 120′.In this example, the top portion 120T of frame element 120 andconductive element 910 extend beyond the end of substrate 265. In thesecond frame, the bottom portion 120B′ of frame element 120′ andconductive element 910′ extend beyond the edge of substrate 265′.Conductive elements 910 and 910′ are electrically coupled through aconductive element 1030, which may be, for example, a metallic conductoror a conductive adhesive, conductive glue, or conductive tape. FIG. 10Bshows one embodiment of electrically coupling light panels 100; however,this specific method is not a limitation of the present invention, andin other embodiments other methods of electrically coupling light panels100 may be employed.

In various embodiments, wires may be soldered or otherwise electricallycoupled to power conductors 210, 220, and multiple light panels 100 maybe electrically coupled through standard wiring techniques, for exampleusing connectors, wire nuts, soldering, or the like. For example, invarious embodiments connectors may be formed on frame elements 120 andelectrically conductive jumpers may be used to electrically coupleadjacent light panels 100. While much of the discussion herein has beenrelated to lighting systems in which the light panels are butted up nextto each other, this is not a limitation of the present invention, and inother embodiments one or more light panels in a system may be spacedapart from the others. In such embodiments, relatively longer jumpersmay be used to connect the light panels together.

In various embodiments, a frame element 120 may include more than oneconductive element 910. For example, conductive elements in frameelement 120 may be used, in addition to powering light panel 100, toprovide communication and control signals to and from light panel 100.In various embodiments, conductive elements in or on frame 120 may beused to provide electrical crossovers, i.e., to permit additionalcircuitry complexity while still using only one layer of conductiveelements 260 on substrate 265. For example, FIG. 11A shows an electricalschematic of a system having two different LEEs 230, 230′. In variousembodiments, LEE 230 may have a different color than LEE 230′, or adifferent intensity, or a different light distribution pattern, or adifference in any other electrical and/or optical property. In variousembodiments, LEEs 230 and 230′ may both emit white light, but withdifferent color temperatures, and the color temperature of the lightpanel may be adjusted by changing the light intensity emitted by stringswith different color-temperature LEEs. For example in variousembodiments LEEs 230 may have a correlated color temperature (CCT) ofabout 2000K and LEEs 230′ may have a CCT of about 10,000K, and the CCTof the ensemble may be varied between about 2000K and about 10,000K byvarying the power delivered to strings having LEEs 230 and 230′. Invarious embodiments, LEEs 230 may have a CCT of about 2700K and LEEs230′ may have a CCT of about 6000K, and the CCT of the ensemble may bevaried between about 2700K and about 6000K by varying the powerdelivered to strings having LEEs 230 and 230′.

In various embodiments, the lighting system is driven by a substantiallyconstant voltage supply that is pulse-width modulated, that is thevoltage is kept substantially the same during the “on” phase and thelight intensity is varied by changing the duty cycle, or the ratio of“on” to “off” time of the power signal. The circuit of FIG. 11A requiresthe power to the two different types of strings to be modulatedseparately, and thus requires three, or perhaps four (if separatereturns are required) conductors. As shown in the schematic of FIG. 11A,this may require an electrical cross-over. While light sheets withmultiple conductive layers may be manufactured, these are relativelymore expensive. In various embodiments of the present invention,conductive elements within frame element 120 may form one or moreelectrical cross-overs, permitting circuits such as that shown in FIG.11A to be realized with a light sheet with only one conductive layer.

FIG. 11B shows one example of a pattern of power conductor traces forpower conductors 220 and 220′, that, combined with the frame element ofFIG. 11C, permit realization of circuits requiring crossovers with alight sheet having a single conductive layer. FIG. 11B shows a portionof a light sheet, including substrate 265 on which power conductors 220and 220′ as well as conductive elements 260 have been formed.

Conductive elements 260 electrically couple LEEs 230, such that LEEs230′ are electrically coupled to power conductor 220′ and LEEs 230 areelectrically coupled to power conductor 220. However, as shown in FIG.11B, power conductor 220 is discontinuous and requires a crossover in aregion 1100 to form a complete circuit. FIG. 11C shows a cross-sectionof the structure of FIG. 11B through cut-line A-A′. As shown in FIG.11C, conductive element 910 associated with power conductor 220 in topframe 120T is formed such that it does not electrically couple withpower conductor 220′. In various embodiments, this may be achieved byspacing conductive element 910 apart from power conductor 220′, while inother embodiments an insulating layer, for example plastic or insulatingtape or paper may be positioned between power conductor 220′ andconductive element 910. Not shown in FIG. 11C is conductive element910′, which is associated with power conductor 220′, in top frameelement 120T. FIG. 11D shows a plan view of the inside of top frameelement 120T, showing both conductive elements 910 and 910′, whereconductive element 910 has region 1100 that is designed to preventelectrical coupling to the underlying portion of power conductor 220′.

While FIGS. 11A-11D show a system having one level of cross-over, thisis not a limitation of the present invention, and in other embodimentsmore than one level of cross-over may be utilized. In variousembodiments, two levels may be utilized, with a light panel having twoframe elements, with each frame element having one level of cross-over.In various embodiments, more than one level of cross-over may beutilized in a single frame element 120. It should be noted that thesystem shown in FIG. 11B has three LEEs 230 in each string; however,this is not a limitation of the present invention, and in otherembodiments more LEEs may be utilized in each string. While FIG. 11Cshows one form of cross-over, this is not a limitation of the presentinvention, and in other embodiments other types of cross-overs may beformed. For example, cross-overs may be formed using any of theapproaches described herein for electrically coupling multiple frameelements together.

In various embodiments, additional elements may be added to frameelement 120 to provide added functionality. For example, in variousembodiments frame element 120 may include one or more spacers 1210 tospace light panel 100 away from a mounting surface 1220, as shown inFIG. 12A. In various embodiments, frame element 120 may include spacersto aid in maintaining a specific gap between the light sheet and anoverlying optic, diffuser or translucent panel, and/or graphic panel1240. (Herein, a “graphic panel” is a panel overlying a lighting systemthat includes therein or thereon a pattern (e.g., words, images,graphics, etc.) for display when illuminated by the lighting system.) Invarious embodiments, such spacers may be fixed spacers 1230, as shown inFIG. 12B, or they may be adjustable spacers 1250, for example as shownin FIG. 12C where the spacers 1250 screw into the frame element 120,thereby controlling the offset distance. In various embodiments,diffuser 1240 may be positioned along the shaft of spacer 1250, forexample by using clamps, a threaded shaft and bolts, or by other means.In various embodiments, frame element 120 may include a track or slot1260 to hold one or more overlying panels or diffusers, as shown in FIG.12D.

While FIGS. 12B-12D show one or more spacers 1230 attached to (or partof) frame element 120, this is not a limitation of the presentinvention, and in other embodiments one or more spacers 1230 may bedisposed on light sheet 110, for example on light sheet 110 between LEEs230. In various embodiments, spacers 1230 may be positioned, shaped, orconstructed of one or more materials to minimize the impact of thespacer on the spatial and/or spectral light distribution. For example,in various embodiments of the present invention, a spacer or a portionof a spacer may include or consist essentially of a transparentmaterial. In various embodiments, a spacer or a portion of a spacer maybe reflective to a wavelength of light emitted by LEEs 230. For example,the spacer (or portion thereof) may have a reflectance greater than 75%to a wavelength of light emitted by LEEs 230. In various embodiments ofthe present invention, a spacer or a portion of the spacer may havespecular reflectance or a diffuse reflectance. In various embodiments, aspacer or a portion of a spacer may have a white surface or be coatedwith a white material having a diffuse reflectance to a wavelength oflight emitted by LEEs 230. In various embodiments, a portion of theconductive trace material may be removed from the substrate in one ormore spacer regions, for example to aid in positioning of the spacer. Invarious embodiments, a portion of the substrate material may be removedin one or more spacer regions, for example to facilitate the mounting ofthe spacer to the underlying support structure.

In various embodiments, light sheets may be electrically connectedtogether through an array of conductive elements mounted over themounting surface. FIG. 13A shows an example of such a system thatincludes or consists of power elements 1310 and 1320 to which one ormore light sheets 110 may be electrically coupled and mechanicallyattached. Power elements 1310 and 1320 may be metallic conductors, forexample wires, bare wires, or bus bars, that are mounted on the mountingsurface. In this approach, the layout of power elements 1310 and 1320 inpart determines the position of light sheets 100, i.e., they determinethe position in one direction, while the position in the orthogonaldirection may be varied by moving the light sheet along the powerelements. As shown in FIG. 13A, light sheets 110 may be spaced apart;however, this is not a limitation of the present invention, and in otherembodiments they may be butted together to maintain LEE 230 pitchbetween adjacent light sheets 110. In various embodiments, light sheet110 may be electrically and mechanically coupled to power elements 1310,1320 by a clamp mechanism, for example a clamp 1340, as shown in FIG.13B. Other methods for electrically coupling and mechanically attachinglight sheet 110 to power elements 1310, 1320 include conductive tape,adhesive, screws, rivets, or the like. In various embodiments, a frameelement may be combined with this approach to permit attachment andelectrical coupling of the light panel to the power elements by anattachment in frame element 120. One aspect of this approach is thatlength adjustment of light sheet 110 may be accomplished by cutting thelight sheet itself and mounting it to power elements that have beenpreviously fabricated to the desired length. In various embodiments, thefeatures described with respect to FIGS. 12A-12D may be incorporatedinto this embodiment featuring an array of power lines. In variousembodiments, one or more signal or control lines may also beincorporated to provide a means for control and communication to one ormore light panels or light sheets, or signals may be incorporated ormodulated on the power supply lines.

FIG. 14 shows an example of a lighting system of the present invention,including power supply or driver 860 and four light panels 100. Whilefour light panels are shown in FIG. 14, this is not a limitation of thepresent invention, and in other embodiments fewer or more light panelsmay be incorporated. In some embodiments, a system may include more than20 light panels or more than 100 light panels. In various embodiments,wires 830 and 830′ may be connected to the same edge of light panel 100,as shown in FIG. 14, in contrast to the wiring schematic shown in FIG.8C. In the system of FIG. 14, each light panel 100 includes powerconductors 210, 220. Power conductors 210 are electrically coupled towire 830, while power conductors 220 are electrically coupled to wire830. In this way, the array of light panels 100 may be energized fromonly one side of the array. (Not shown in FIG. 14 for clarity, butdiscussed herein, are optional frame 120 and electrical connectionsbetween power conductors 210, 220 on adjacent sheets.)

In various embodiments, driver 860 is a substantially constant voltagesupply, the output of which is pulse-width modulated to permit dimmingof LEEs 230 on light panels 100. In various embodiments, the lightingsystem is a UL class 2 system having an operating voltage not exceeding60 V.

In various embodiments, light panel 100 is square, having a sidedimension in the range of about 10 cm to about 100 cm. In variousembodiments, LEE pitches 223 and 225 are each in the range of about 5 mmto about 50 mm.

While frame elements 120 in FIGS. 5A-5D, 6, 7A, 7B, 8A, and 8C have beendepicted as straight or substantially straight, this is not a limitationof the present invention, and in other embodiments frame elements mayhave more than one straight portions, as shown in FIG. 15A, or may becurved, as shown in FIG. 15B, or may include straight or curvedelements, as shown in FIG. 15C. The shape or geometry of frame element120 is not a limitation of the present invention. For example, thestructure shown in FIG. 15B may be used to form a free-standing orpartially free-standing light panel structure as shown in FIG. 15D, ormay be mounted to a shaped surface having substantially the same shapeas the shaped light panel, as shown in FIG. 15E. In various embodiments,structures such as those shown in FIGS. 15D and 15E may also be formedusing flexible or semi-rigid light panels.

In various embodiments of the present invention, the light panel may bepositionable. In such embodiments, the light panel may be flexible, butwhen deformed, it retains the deformed position, or substantially thedeformed position, after the deforming force is removed. Suchembodiments may also be used to form structures such as those shown inFIGS. 15A-15E. In various embodiments, a positionable frame element 110may include or consist essentially of a flexible material combined witha deformable but relatively inflexible material, such as a wire. FIG. 16depicts a cross-section of an exemplary positionable frame elementincluding a flexible body 1610 surrounding a wire or positionableelement 1620; however, this is not a limitation of the presentinvention, and in other embodiments other means may be utilized toconstruct a positionable frame element or a positionable light panel.

In various embodiments of the present invention, light panel 100 may bewater-resistant or waterproof. In various embodiments, light panel 100may meet IP65, IP66, IP67, or IP68 environmental ratings. (One methodfor rating different levels of environmental protection is an IP ratingas specified by International Protection Marking in InternationalElectrotechnical Commission (IEC) standard 60529, providingclassification of degrees of protection provided by enclosures forelectrical equipment, the entirety of which is hereby incorporated byreference herein. In general for an IP XY rating, “X” indicates thelevel of protection for access to electrical parts and ingress to solidforeign objects, while “Y” indicates the level of protection for ingressof harmful water. For example, an IP44 rating provides access andingress protection for objects greater than about 1 mm and protectionfrom water splashing on the system. In another example, an IP66 ratingprovides a dust-tight enclosure and protection from water jets incidenton the system. Specific details of the requirements and test method aredetailed within the IP specification.) In various embodiments, lightsheet 110 may be encased or encapsulated in a waterproof orsubstantially waterproof coating, for example including or consistingessentially of silicone, polyurethane, or the like, as detailed in U.S.patent application Ser. No. 14/301,859, filed on Jun. 11, 2014, theentire disclosure of which is incorporated by reference herein. Invarious embodiments, the coating may be a conformal coating, for examplehaving a thickness in the range of about 20 μm to about 1000 μm. Invarious embodiments, light sheet 110 may be potted, encased orencapsulated in a layer of waterproof or substantially waterproofmaterial, for example silicone or polyurethane or the like.

In various embodiments of the present invention, a lighting system mayinclude or consist essentially of multiple light panels 100, as shown inFIG. 17A. FIG. 17A shows six light panels 100, arranged in a 2×3 array;however, this is not a limitation of the present invention, and in otherembodiments other array geometries or layouts may be used. For example,light panels 100 in FIG. 17A are tiled together such that the edges ofadjacent light panels 100 meet or are relatively close together, forexample such that the LEE pitch between two adjacent light panels 100(that is the LEE pitch that spans across the edges of two adjacent lightpanels 100) is the same or substantially the same as the LEE pitchwithin a single light panel 100. However, this is not a limitation ofthe present invention, and in other embodiments light panels 100 may bespaced apart, for example in a substantially regular pattern, forexample as shown in FIG. 17B or in an arbitrary pattern, for example asshown in FIG. 17C. Electrical connections between light panels 100 arenot shown for clarity in FIGS. 17A-17C. While FIGS. 17A-17C depict lightpanels 100, this is not a limitation of the present invention, and inother embodiments similar configurations may be formed using lightsheets 110.

In various embodiments of the present invention, the means forelectrical coupling to or between light panels 100 or light sheets 110may include or consist essentially of a vertical connector, in which theconnection mechanism is activated or deactivated by movement of at leastone connector component in a direction substantially perpendicular tothe surface of the light panel in the region of the connector. FIG. 18Ashows one embodiment of a vertical connector that includes or consistsessentially of a pin 1810 that mates with a socket 1820. In variousembodiments of the present invention, pin 1810 is electrically coupledand/or mounted on conductive trace 210. Wire 1830 is electricallycoupled to socket 1820 and may be used to provide electrical coupling(i.e., provide electrical power and/or communication and/or controlsignals) through socket 1820 and pin 1810 to one or more conductivetraces 210 disposed over substrate 265. FIG. 18B shows anotherembodiment of the present invention in which the vertical socket 1820fits over pin 1810 and a portion of pin 1810 protrudes through and isvisible over the socket 1820 when the socket 1820 is in place. Suchconnectors may include, for example the 400 series connectors availablefrom Bender & Wirth GmbH & Co of Kierspe, Germany.

FIG. 18C shows another embodiment of the present invention that featuresa snap connector including or consisting essentially of at least twoparts, identified in FIG. 18C as a button 1840 and a button socket 1850.Button 1840 and button socket 1850 are shown as disengaged in FIG. 18Cand engaged in FIG. 18D. In some embodiments of the present invention,button 1840 is electrically coupled and/or mounted on a conductive trace210. As with the vertical connector shown in FIG. 18A, button socket1850 may be electrically coupled to one or more wires 1830. In variousembodiments, light panels may be electrically coupled by a jumper 1860between two connectors, as shown in FIG. 18D.

In various embodiments of the present invention, button socket 1850 maybe mounted on or to one light sheet 110, and button 1840 may be mountedon or to a second light sheet 110′, permitting direct connection betweentwo light panels, as shown in FIG. 18E. In various embodiments of thepresent invention, button 1840 and button socket 1850 may be formed onopposite sides of the two light sheets, for example either the button1840 or button socket 1850 may be mounted on the front surface of onelight sheet while the mating connector may be mounted on the backsurface of a second light sheet. For example, in the structure shown inFIG. 18E, button 1840 is mounted on the front side of light sheet 110and button socket 1850 is mounted on the back side of light sheet 110′.As shown in FIG. 18E, a via 1860 electrically couples button socket 1850to conductive trace 210′ through substrate 265′. In various embodimentsof the present invention, via 1860 may include or consist essentially ofa rivet, a staple, a crimp or piercing connector, or the like. Invarious embodiments of the present invention, button 1840 and buttonsocket 1850 may be formed on the same side of the light sheet; forexample, as shown in FIG. 18F, button 1840 and button socket 1850 areformed on the same side (e.g., front side) of light sheets 110 and 110′,and a portion of light panel 110′ is folded over to facilitateconnection of button socket 1850 to button 1840.

In various embodiments of the present invention, the snap connector mayinclude or consist essentially of a 9V battery connector. 9V batteryconnectors have male and female components, as shown in FIGS. 18G and18H respectively.

In various embodiments of the present invention, the snap connectors maybe electrically coupled to conductive trace 210 and/or mechanicallycoupled to conductive trace 210 and/or substrate 265 using a variety ofmeans, for example solder, conductive adhesive, anisotropic conductiveadhesive, eyelets, rivets, crimp connectors, piercing connectors, or thelike. The method of attachment of the snap connectors to a light sheetor light panel is not a limitation of the present invention.

FIG. 19A shows one embodiment of a light sheet 110 that features LEEs230 and connectors 1910, 1910′, 1920, and 1920′ disposed on substrate265. Conductive traces providing electrical coupling between LEEs 230and current control elements and power conductors 1960 and 1970 are notshown for clarity in FIG. 19A. In various embodiments of the presentinvention, connectors 1910, 1910′, 1920, and 1920′ may include, consistessentially of, or consist of vertical connectors or snap connectors;however, this is not a limitation of the present invention and in otherembodiments other forms of connectors may be used. In variousembodiments of the present invention, connectors 1910 and 1910′ mayinclude or consist essentially of female 9V battery connectors as shownin FIG. 18H, and connectors 1920 and 1920′ may include or consistessentially of male 9V battery connectors as shown in FIG. 18G. In theembodiment shown in FIG. 19A, the connectors are all disposed on thesame side of light sheet 110; however, this is not a limitation of thepresent invention, and in other embodiments various connectors may beformed on different sides of light sheet 110, for example as discussedin reference to FIG. 18E. In various embodiments, the connectors may beused to provide power to the light sheet. For example, in variousembodiments of the present invention, power to light sheet 110 may beprovided through connectors 1910′ and 1920′. For example, in variousembodiments, connector 1910′ may be used for the positive power supplyconnection and connector 1920′ may be used for the negative or groundpower supply connection; however, this is not a limitation of thepresent invention, and in other embodiments other configurations forpowering the light sheet may be utilized.

In various embodiments of the present invention, for example as shown inFIG. 19A, connectors 1920′ and 1910 may be electrically coupled togetherby an electrical trace 1960 (shown in FIG. 19A as a dashed line), andconnectors 1910′ and 1920 may be electrically coupled together by aconductive trace 1970 (shown in FIG. 19A as a dashed line). In variousembodiments of the present invention, multiple light sheets 110 may beelectrically coupled together, for example by connecting connector 1910on a first light sheet to connector 1920′ on a second light sheet and byconnecting connector 1920 on a first light sheet to connector 1910′ on asecond light sheet.

In various embodiments of the present invention, one or more connectorsmay be positioned on a tab extending out from the main portion of thelight sheet, for example tab 1930 as shown in FIG. 19A. In variousembodiments of the present invention, a portion of tab 1930 may befolded over (see, e.g., folded portion 1931 in FIG. 19B), for example asdiscussed in reference to FIG. 18F, to facilitate connection to anotherlight sheet. FIG. 19B shows a schematic of a portion of a tab 1930containing connector 1920 disposed on a partially folded-over portion1931, while FIG. 19C shows a schematic of a portion of tab 1930containing connector 1920 in a completely or substantially completelyfolded-over position. In various embodiments of the present invention,the folded-over portion may be held in place by an adhesive, glue, tapeor the like, for example adhesive 1980 in FIG. 19B. In variousembodiments of the present invention, a portion of connector 1920 mayextend through a portion of folded portion 1931 or portions of both tab1930 and folded portion 1931. FIG. 19D shows an example of an embodimentof the present invention featuring light sheet 110 having a tab 1930with a portion 1931 folded over prior to the connector being disposed onthe sheet. In this example, the connector includes or consistsessentially of two parts, identified as a back connector part 1921 and afront connector part 1922, which are mated through a hole 1923. In thisexample, hole 1923 is formed through both tab 1930 and the folded overportion of tab 1931 prior to completing formation of the connector.However, this is not a limitation of the present invention, and in otherembodiments, one or both of back connector part 1921 and front connectorpart 1922 may pierce or otherwise form a hole in tab 1930 and/or foldedportion of the tab 1931 during placement of the connector. In theexample shown in FIG. 19D, mating of back connector part 1921 and frontconnector part 1922 may include mechanically bringing the two partstogether and deforming a portion of one or both connector parts to bindthe two portions together. The structure of the connector and/or themethod of forming a connector from two or more connector parts are notlimitations of the present invention.

In various embodiments of the present invention, a folded portion 1990of the light sheet may be folded over, for example as shown in FIG. 19E.In various embodiments, all or a portion of power conductor 210 or 220,for example as shown in FIG. 2C, may be disposed on or in the foldedportion 1990. In various embodiments, the placement of all or a portionof power conductor 210 or 220 on folded portion 1990 may be used todecrease the resistance per unit length of the power conductor, for agiven width light sheet, by increasing the effective width of powerconductor 210 or 220. As shown in FIG. 19E, light sheet 100 has a width1992, not including folded portions 1990. Folded portions 1990 each havea width 1997. FIG. 19F shows a detailed schematic of a portion of lightsheet 110, showing a comparison of light sheet 110 with and without afolded portion 1990. Light sheet 110 without folded portion 1990 haspower conductor 210 having a width 1994. Light sheet 110 with foldedportion 1990 has power conductor 210′ having an additional width 1996,for a total width equal to the sum of width 1994 and width 1996. For apower conductor 210 having a substantially constant thickness andresistivity, the resistance per unit length is inversely proportional tothe width of power conductor 210. For the example shown in FIG. 19E, theconductance of power conductor 210′ (including portions 1994 and 1996)is (1994+1996)/1994 times that of power conductor 210 (having width1994). In various embodiments of the present invention, folded portion1990 may have a width 1996 in the range of about 2 mm to about 50 mm. Invarious embodiments of the present invention, power conductor 210 mayhave a width of 1994 of about 3 mm and power conductor 210′ may have awidth (1994+1996) of about 9 mm, resulting in power conductor 210′having a resistance about 3× lower than that of power conductor 210. Invarious embodiments of the present invention, power conductor 210′ mayhave a resistance in the range of about 1.5 to about 10 times lower thanthat of power conductor 210. While FIG. 19F shows one folded portion1990, this is not a limitation of the present invention, and in otherembodiments light sheet 110 may have multiple folded portions. Forexample FIG. 19G shows light sheet 110 having two folded portions 1990and 1990′. However, this is not a limitation of the present invention,and in other embodiments light sheet 110 may have more than two foldedportions. While FIG. 19G shows the folds in a fan-fold configuration,this is not a limitation of the present invention and in otherembodiments the folding configuration may be different. For example invarious embodiments the folds may be rolled-over or folded over, asshown in FIG. 19I, or may have other fold configurations or combinationsof configurations. In various embodiments, the folded portions or partsof the folded portions may be adhered or fastened to each other or tothe unfolded part of the light sheet, for example using glue, adhesive,tape, lamination, staples, rivets, or the like. In various embodimentsof the present invention, light sheets 110 having folded portions 1990may be combined with frame elements, for example frame elements 120,120′. In various embodiments of the present invention, folded portion1990 of light sheet 110 may be folded or wrapped around a portion offrame element 120 or 120′ as shown in FIG. 19H; however, this is not alimitation of the present invention, and in other embodiments foldedportion 1990 of light sheet 110 may be disposed under or over frameelement 120, 120′, or light sheet 110 with one or more folded portions1990 may be utilized without any frame elements.

In various embodiments of the present invention, a portion of lightsheet 110 may be adhered or attached to frame 120 or to a portion offrame 120, for example using adhesive, glue, tape, double-sided tape, orthe like. For example, in various embodiments a portion of light sheet110 may be adhered to a portion of frame 120, for example all,substantially all or a portion of the top and/or the bottom and/or thesides of frame 120 may be adhered to light sheet 110. In variousembodiments of the present invention, a lighting system may include orconsist essentially of an assemblage of multiple light sheets 110 and/orlight panels 100 and an associated connector system. In variousembodiments of the present invention, the connector system utilizes thesame type of connectors, or snap connectors or 9V battery connectorsthat are used on light sheets 110 and/or light panels 100.

While FIG. 19F shows portions 1994 and 1996 having the same orsubstantially the same shape, this is not a limitation of the presentinvention, and in other embodiments they may have different shapes. Forexample, FIG. 19J shows an example of an embodiment of the presentinvention in which portion 1994 has a different shape than that ofportion 1996. While FIG. 19F shows portions 1994 and 1996 as onecontiguous area, this is not a limitation of the present invention, andin other embodiments portions 1994 and 1996 may have one or more spacesbetween them or gaps 1997 (areas not containing the electricallyconductive trace material) in them, for example as shown in FIGS. 19Kand 19L.

In various embodiments the light panel, for example as shownschematically in FIGS. 1A, 2B, 19H, and other figures herein, may have athickness in the range of about 0.25 mm to about 20 mm, or in the rangeof about 0.4 mm to about 5 mm.

FIGS. 20A and 20B show two types of light sheets or light panels 2010and 2020, respectively, in accordance with embodiments of the presentinvention. Panel 2010 has tabs 1930, each of which has a connectordisposed thereon. Panel 2020 does not have tabs 1930, and the connectorsare disposed on the main panel body of the light panel or light sheet(e.g., near the periphery and/or corners of the panel or sheet). In thisembodiment of the present invention, the connector system includes orconsists essentially of two mating connectors 2030 and 2040. (Physicallysimilar or identical connectors, but formed in different locations onthe light sheet or light panel are identified by one or moreapostrophes, for example 2030 and 2030′ are the same physical type ofconnector, but disposed in different locations on the light sheet orlight panel.) Connectors 2030 and 2040 mate to each other and in someembodiments of the present invention are polarized (e.g., one connectoris male and the other is female) to prevent misconnection of the lightpanels or light sheets. However, this is not a limitation of the presentinvention, and in other embodiments connectors 2030 and 2040 may not bepolarized. In the schematics of FIGS. 20A-20C, connectors 2030 areidentified by the grey filled-in circles, and connectors 2040 areidentified by the white filled-in circles. In various embodiments of thepresent invention, when multiple light sheets or light panels areconnected, connector 2040 is electrically coupled to connector 2030′ andconnector 2030 is electrically coupled to connector 2040′, for exampleas discussed in reference to FIG. 19A. This permits multiple lightpanels or light sheets to be electrically coupled through theseconnectors, for example as discussed in reference to FIG. 20C below.

In various embodiments of the present invention, other connectorconfigurations may be utilized, for example a portion of one sheet mayoverlap a portion of an adjacent sheet to permit alignment and mating ofthe electrical connectors. In various embodiments of the presentinvention, the electrical connectors may be mated by coupling in adirection parallel to or substantially parallel to the surface of thelight sheet.

FIG. 20C shows an embodiment of a lighting system of the presentinvention that is partially assembled, and that includes or consistsessentially of three panels 2010, 2010′, and 2010″ and one panel 2020.Panels 2010′ and 2010″ have been electrically coupled together. Panel2010 is awaiting assembly, which is completed by connecting connector2040′ on panel 2010 to connector 2030′ on panel 2010′ and connectingconnector 2030 on panel 2010 to connector 2040 on panel 2010′. Panel2020 is awaiting assembly into the lighting system, which is completedusing jumpers 2050, 2050′ (jumper 2050′ has already been connected) byconnecting connector 2030′″ on jumper 2050 to connector 2040″ on panel2010″ and connecting connector 2040′″ on jumper 2050 to connector 2030″on panel 2020. Jumper 2050 may have any length and may be straight, asshown in FIG. 20C, or may be curved or have any shape. While jumper 2050is shown in FIG. 20C as connecting a 2010-type panel to a 2020-typepanel, this is not a limitation of the present invention, and in otherembodiments one or more jumpers 2050 may connect two 2010-type panels(i.e., panels having one or more protruding tabs) or two 2020-typepanels (i.e., panels lacking protruding tabs) or any other style orconfiguration of panels. In various embodiments of the presentinvention, the connectors on the left side (top and bottom) of eachlight sheet or light panel are electrically coupled together and theconnectors on the right side (top and bottom) of each light sheet orlight panel are electrically coupled together, permitting multiple lightsheets or light panels to be powered by connection from one end of thearray of light panels or light sheets (i.e., from one end of theassembled lighting system). The order of assembly of the components withreference to FIG. 20C (including but not limited to light sheets, lightpanels, and jumpers) is one example of how these components may beassembled. In other embodiments of the present invention, the assemblyorder may be different and/or other components may be utilized.

In various embodiments of the present invention, jumper 2050 may beconstructed in a similar fashion to the light panel, while in otherembodiments, jumper 2050 may have a different construction from that ofthe light panel. In various embodiments of the present invention, jumper2050 may include or consist essentially of one or more wires or wireharnesses with connectors. In various embodiments of the presentinvention, jumper 2050 may include or consist essentially of a flexiblesubstrate having conductive traces disposed on the substrate andconnectors electrically coupled to the conductive traces (i.e., in thestyle of light sheets as described herein).

In various embodiments of the present invention, a light sheet or lightpanel may have one or more connector wires directly attached to one ormore power conductors or other conductive elements. In such embodiments,the other end of the wire (the end not electrically coupled to a portionof the light sheet or light panel) may be a flying lead, i.e., just thewire, or may be terminated with a connector, or may be integrated into awiring harness, or may be contacted by other means.

In various embodiments of the present invention, jumpers may be used toelectrically couple one or more light panels or light sheets to a powerbus or power supply. FIG. 21A shows a lighting system including orconsisting essentially of nine light panels or light sheets 2010. Thenine light panels have been connected into three vertically orientedgroups of three panels each, and the system is ready for connection to apower supply. While the system of FIG. 21A shows a lighting systemincluding or consisting essentially of nine light sheets or lightpanels, this is not a limitation of the present invention, and in otherembodiments the lighting system may have fewer or more light sheets orlight panels.

In various embodiments of the present invention, a power bus or powerwiring harness 2110 may include or consist essentially of one or morepower conductors, for example power conductors 2120 and 2130, and one ormore connectors, for example connectors 2030′″ and 2040′″ (otherconnectors are shown in FIG. 21A, but not identified with separateidentification numbers). In various embodiments, connector 2030′″ iselectrically coupled to power conductor 2120 and connector 2040′″ iselectrically coupled to power conductor 2030 (other connectors are shownas electrically coupled, but not identified in FIG. 21A with separateidentification numbers). To continue assembly of the lighting system,connector 2030′″ on power bus 2110 is connected to connector 2040 onjumper 2050′, connector 2040′″ on power bus 2110 is electricallyconnected to connector 2030 on jumper 2050, connector 2030′ on jumper2050′ is electrically connected to connector 2040″ on panel 2010′, andconnector 2040′ on jumper 2050 is electrically connected to connector2040″ on panel 2010′. While the system shown in FIG. 21A uses lightpanels or light sheets with protruding tabs, this is not a limitation ofthe present invention, and in other embodiments tab-less panels may beused or a mixture tabbed and tab-less panels may be used, or any othertype or style of light sheets or panels may be used. While the systemshown in FIG. 21A shows panels 2010 as close coupled, i.e., all of thepanels are connected together with relatively little space between eachpanel, both in the horizontal and vertical directions, this is not alimitation of the present invention, and in other embodiments,additional space between adjacent panels, for example in the horizontaldirection or vertical direction or both directions may be part of thepresent invention.

In various embodiments of the present invention, the light sheets orlight panels are configured and positioned such that the distancebetween adjacent LEEs between adjacent light sheets or light panels isthe same or substantially the same as the distance between adjacent LEEson one light sheet or light panel, i.e., the pitch between LEEs on alight panel or light sheet is the same or substantially the same as thepitch between adjacent LEEs across the joint or interface between twoadjacent light sheets or light panels. In various embodiments of thepresent invention, the lighting system includes or consists essentiallyof multiple light panels or light sheets and the pitch or distancebetween adjacent LEEs is the same, independent of whether the LEEs areon one light sheet or light panel or on separate light panels or lightsheets. In various embodiments of the present invention, the LEEs arespaced in a rectangular array on the light sheet or light panel with afirst pitch in a first direction and a second pitch in a seconddirection that is substantially perpendicular to the first direction,and the system includes or consists essentially of multiple light sheetsor light panels, and the pitch in the first direction between adjacentlight sheets is the same as the first pitch on the light sheet or lightpanel, and the pitch in the second direction between adjacent lightsheets is the same as the second pitch on the light sheet or lightpanel. For example, in various embodiments, the pitch between all LEEsin a system including multiple light panels, for example the systemshown in FIG. 21A, is the same or substantially the same.

While the lighting system shown in FIG. 21A includes nine light panelsor light sheets 2010, this is not a limitation of the present invention,and in other embodiments fewer or more light panels and/or light sheets2010 may be utilized. In various embodiments of the present invention, alighting system may include or consist essentially of at least 50 lightpanels and/or light sheets, or at least 100 light panels and/or lightsheets, or at least 500 light sheets and/or light panels, or at least5000 light sheets and/or light panels

FIG. 21B shows an embodiment of a lighting system of the presentinvention similar to that of the lighting system of FIG. 21A; however,in the system of FIG. 21B, power bus or power wiring harness 2111differs from power bus or power wiring harness 2110 by elimination ofjumpers 2050. Jumpers 2050 are replaced by tabs or extensions 2140 onwhich are disposed the connectors that connect to a connector on a lightsheet or light panel. In various embodiments of the present invention,tabs or extensions 2140 may each include one connector; however, this isnot a limitation of the present invention, and in other embodiments atab or extension 2140 may include more than one connector, as shown bytab or extension 2150. While tab or extension 2150 includes twoconnectors, this is not a limitation of the present invention, and inother embodiments tab or extension 2150 may include more than twoconnectors. In various embodiments of the present invention, power busor power wiring harness 2111 does not include tabs or extensions 2140 or2150, and the connectors are formed on the body of power bus or powerwiring harness 2111, as shown in FIG. 21C. In various embodiments of thepresent invention the power bus or power wiring harness includes orconsists essentially of one or more wires, optionally bundled togetherwith connectors wired to the main power lines in the power bus.

In various embodiments of the present invention, the connectors on theleft side (top and bottom) of each light sheet or light panel areelectrically coupled together and the connectors on the right side (topand bottom) of each light sheet or light panel are electrically coupledtogether, permitting multiple light sheets or light panels to be poweredby connection from one end of the array of light panels or light sheets.For example, in the lighting system of FIG. 21B, a power supply 2170provides power through power bus 2111 to the bottom three light panels.This power is then conveyed through the bottom light sheet or lightpanel to the light sheet or light panel to which it is electricallycoupled, and so on. For example, light panel 2010 is powered from powerbus 2111, light panel 2010′ is provided power from light panel 2010, andlight panel 2010″ is provided power from light panel 2010′. In variousembodiments of the present invention, this permits powering orenergizing of large linear assemblies of light panels or light sheetswith only one power connection, and in some embodiments from only oneend of the assembly. In various embodiments of the present invention,different configurations of connection of two or more connectors may beutilized.

In the example in FIG. 21B, power bus 2111 is electrically coupled topower supply 2170. In various embodiments of the present invention,power supply 2170 provides power to energize light panels 2010. Invarious embodiments of the present invention, power supply 2170 providesa constant voltage power to power bus 2111; however, this is not alimitation of the present invention, and in other embodiments powersupply 2170 may provide constant current, AC-based power, or any othertype of power. In various embodiments of the present invention, powersupply 2170 is energized from a mains power supply, for example an ACmains power source; however, this is not a limitation of the presentinvention, and in other embodiments power supply 2170 may be energizedfrom a battery or batteries, rechargeable battery or batteries,photovoltaic generation systems, wind generation systems, gas or otherfuel based generator systems, energy harvesting systems, another powersupply, or other power sources. In various embodiments of the presentinvention, power supply 2170 may provide a constant voltage that ismodulated, for example using pulse-width modulation (PWM), to permitdimming of light-emitting elements on light panels 2010; however, thisis not a limitation of the present invention, and in other embodimentsdimming may be accomplished by other means, for example by modificationof the current to each light panel, modification of the voltage to eachlight panel, or by other means.

In various embodiments of the present invention, a power bus or powerwiring harness 2111 or 2112 may also support control or communicationsignals to the light sheets or light panels, or from the light sheets orlight panels, for example to provide control and/or communicationsignals between a power source, for example power supply 2170 and lightpanels 2010. In various embodiments, control or communication signalsmay be used to selectively energize or de-energize individual or groupsof light panels or light sheets in a lighting system, or to selectivelyenergize or de-energize portions of individual or groups of light panelsor light sheets or to modify the intensity of light emitted byindividual or groups of light panels or light sheets in a system, or tomodify the intensity of light emitted by portions of individual orgroups of light panels or light sheets, or to modify other opticalcharacteristics of individual or groups of light panels or light sheetsor portions of individual or groups of light panels or light sheets, forexample correlated color temperature (CCT), color rendering index (CRI),R9, spectral power distribution, light distribution pattern, or thelike.

FIG. 21C shows an embodiment of the present invention in which a powerbus or power wiring harness 2112 without tabs or extensions 2140 or 2150is connected to light panels or light sheets 2010. In the lightingsystem of FIG. 21C, the vertical columns of light panels or light sheetsare spaced apart from each other, in contrast to the system of FIG. 21B,in which the light panels or light sheets are positioned substantiallynext to each other. Furthermore, in the system of FIG. 21C, power bus orpower wiring harness 2112 extends beyond the limits of the figure, andmay provide power to one or more additional groups of light sheets orlight panels. The number of groups of light sheets or light panelspowered by the power bus or power wiring harness is not a limitation ofthe present invention.

FIG. 21D shows a schematic of another embodiment of the presentinvention in which power is supplied to multiple columns of light panelsor light sheets from one end of the assembly. Power supply 2170 suppliespower to light sheet 2010, which provides power to light sheet 2010′.Power is then conveyed from light sheet 2010′ through power bus 2112 tolight sheet 2010″, which provides power to light sheet 2010′″. Power isthen conveyed from light sheet 2010′′ through power bus 2113 to the nextarray of light sheets (not shown).

FIG. 21E shows a schematic of another embodiment of the presentinvention in which the connectors are grouped on one tab, with each tabhaving multiple connectors. For example, power bus 2111 has one tabconnecting to each light panel, for example tab 2141 connecting to panel2010. In various embodiments, one tab may include two or moreconnectors, while in other embodiments each connector may include orconsist essentially of multiple separate electrical conductors.

Power buses or power wiring harnesses may incorporate one or more tabsor no tabs, and various types of power buses or power wiring harnessesas well as combinations of various types of power buses or power wiringharnesses are within the scope of this invention.

While the systems shown in FIGS. 19A, 19H, 20A-20C, and 21A-21C depictsubstantially square light panels or light sheets, this is not alimitation of the present invention, and in other embodiments lightpanels or light sheets may have other shapes, for example rectangular,hexagonal, triangular, parallelogram, or any arbitrary shape. WhileFIGS. 21A-21C show square arrays of light sheets or light panels, thisis not a limitation of the present invention, and in other embodimentsthe light sheets or light panels may be configured or positioned in arectangular array, a hexagonal array, a triangular array, or any otherarray, whether periodic or not.

FIG. 21F shows an embodiment of a lighting system of the presentinvention including or consisting essentially of light panels 2010attached to a support 2190 and covered or partially covered by an optic2185 (the details of support 2190 and of optic 2185 are not shown forclarity, nor are they limitations of the present invention). As shown inFIG. 21F, optic 2185 is spaced apart from light panels 2010 by a spacing2180. In various embodiments of the present invention, optic 2185 may bein contact with light panel 2010 or substantially in contact with lightpanel 2010, while in other embodiments optic 2185 may be in contact orsubstantially in contact with the LEEs on light panel 2010, or may bespaced apart from light panel 2010 as shown in FIG. 21F. In variousembodiments of the present invention, spacing 2180 may be in the rangeof about 0.5× to about 5×, or in the range of about 1× to about 2×, thespacing or pitch of LEEs on light panel 2010. In various embodiments ofthe present invention, spacing 2180 may be in the range of about 5 mm toabout 500 mm, or in the range of about 10 mm to about 100 mm. In variousembodiments of the present invention, support 2190 may include orconsist essentially of a wall, ceiling, floor, column, sub-structure,substrate, or other feature to which light panel or panels 2010 may beattached or mounted. In various embodiments of the present invention,optic 2185 may include or consist essentially of a lens, a diffuser, arefractive optic, a reflective optic, a Fresnel optic, a fabric, atranslucent material such as plastic or stone, a graphic panel, amembrane or the like. In various embodiments of the present invention,optic 2185 may include or consist essentially of a plurality of opticalelements, for example as described in U.S. patent application Ser. No.13/693,632, filed on Dec. 4, 2012, the entire disclosure of which isincorporated by reference herein. In various embodiments of the presentinvention, optic 2185 may include or consist essentially of glass,stone, plastic, fabric, foam, paper, or the like.

In various embodiments of the present invention, the total thickness2181 of the lighting system shown in FIG. 21F, i.e., the distancebetween the back of light panel 2010 to the front of optic 2185, may bein the range of about 1× to about 5× the spacing or pitch of LEEs onlight panel 2010, or in the range of about 1.5× to about 4× the spacingor pitch of LEEs on light panel 2010. In various embodiments of thepresent invention, a total thickness 2181 of the lighting system shownin FIG. 21F may be in the range of about 1 cm to about 10 cm, or in therange of about 1.5 cm to about 5 cm.

While a number of the examples described herein include or consistessentially of one or more flexible light sheets and one or more frameelements, this is not a limitation and in other embodiments frameelements may be eliminated, resulting in light panels including orconsisting essentially of one or more flexible light sheets with noframe elements.

While a number of the examples described herein utilize aconstant-voltage drive system for powering one or more light sheets orlight panels, this is not a limitation of the present invention, and inother embodiments other modes of energizing one or more light sheets orlight panels may be utilized, for example constant-current or AC driveor other modes. In some embodiments of the present invention, the modeof powering the light sheets or light panels may determine the type,number, or need for current control elements on each light sheet orlight panel. For example, in some embodiments of the present invention,no current control elements may be required on the light panel or lightsheet, for example if using a constant-current drive mode.

While a number of examples presented herein utilize 9V batteryconnectors for connectorized panels (i.e., panels having one or moreconnectors), this is not a limitation of the present invention and inother embodiments other types of connectors may be utilized. Forexample, such connectors may include commercially available plug andjack or male and female connectors, polarized or unpolarized connectors,or connectors which on one or more ends are connected to a light sheetor light panel by wires.

As utilized herein, the term “light-emitting element” (LEE) refers toany device that emits electromagnetic radiation within a wavelengthregime of interest, for example, visible, infrared or ultravioletregime, when activated, by applying a potential difference across thedevice or passing a current through the device. Examples oflight-emitting elements include solid-state, organic, polymer,phosphor-coated or high-flux LEDs, laser diodes or other similar devicesas would be readily understood. The emitted radiation of an LEE may bevisible, such as red, blue or green, or invisible, such as infrared orultraviolet. An LEE may produce radiation of a continuous ordiscontinuous spread of wavelengths. An LEE may feature a phosphorescentor fluorescent material, also known as a light-conversion material (or awavelength-conversion material, or a phosphor), for converting a portionof its emissions from one set of wavelengths to another. In someembodiments, the light from an LEE includes or consists essentially of acombination of light directly emitted by the LEE and light emitted by anadjacent or surrounding light-conversion material. An LEE may includemultiple LEEs, each emitting essentially the same or differentwavelengths. In some embodiments, a LEE is an LED that may feature areflector over all or a portion of its surface upon which electricalcontacts are positioned. The reflector may also be formed over all or aportion of the contacts themselves. In some embodiments, the contactsare themselves reflective. Herein “reflective” is defined as having areflectivity greater than 65% for a wavelength of light emitted by theLEE on which the contacts are disposed. In some embodiments, an LEE mayinclude or consist essentially of an electronic device or circuit or apassive device or circuit. In some embodiments, an LEE includes orconsists essentially of multiple devices, for example an LED and a Zenerdiode for static-electricity protection. In some embodiments, an LEE mayinclude or consist essentially of a packaged LED, i.e., a bare LED dieencased or partially encased in a package. In some embodiments, thepackaged LED may also include a light-conversion material. In someembodiments, the light from the LEE may include or consist essentiallyof light emitted only by the light-conversion material, while in otherembodiments the light from the LEE may include or consist essentially ofa combination of light emitted from an LED and from the light-conversionmaterial. In some embodiments, the light from the LEE may include orconsist essentially of light emitted only by an LED.

One or more non-LEE devices such as Zener diodes, transient voltagesuppressors (TVSs), varistors, etc., may be placed on each light sheetto protect the LEEs 230 from damage that may be caused by high-voltageevents, such as electrostatic discharge (ESD) or lightning strikes. Inone embodiment, conductive trace segments shown in FIG. 2B between theLEE strings 250 may be used for placement of a single protection deviceper light sheet, where the device spans the positive and negative powertraces, for example power conductors 210, 220. These trace segments alsoserve to provide a uniform visual pattern of lines in the web direction,which may be more aesthetically pleasing than a light sheet withnoticeable gaps between LEE strings 250. In a more general sense, inaddition to conductive traces 260 that are part of string 250,additional conductive traces 260 that may or may not be electricallycoupled to other strings 250 and/or power conductors 210, 220 may beformed on substrate 265, for example to provide additional powerconduction pathways or to achieve a decorative or aesthetically pleasinglook to the pattern on the light sheet or to provide a communicationpathway to one or more CEs 240, for example to provide a control signalto the one or more CEs 240. These trace segments also serve to provide auniform visual pattern of lines in the web direction, which may be moreaesthetically pleasing than a light sheet with noticeable gaps betweenLEE strings 250.

In one embodiment, an LEE 230 includes or consists essentially of a baresemiconductor die (such as an LED), while in other embodiments LEE 230includes or consists essentially of a packaged LED.

In some embodiments, LEE 230 may include or consist essentially of a“white die” that includes an LED that is integrated with alight-conversion material (e.g., a phosphor) before being attached tothe light sheet, as described in U.S. patent application Ser. No.13/748,864, filed Jan. 24, 2013, or U.S. patent application Ser. No.13/949,543, filed Jul. 24, 2013, the entire disclosure of each of whichis incorporated by reference herein.

In some embodiments, LEEs 230 may emit light in a relatively smallwavelength range, for example having a full width at half maximum in therange of about 20 nm to about 200 nm. In some embodiments, all LEEs 230may emit light of the same or substantially the same wavelength, whilein other embodiments different LEEs 230 may emit light of differentwavelengths. In some embodiments LEEs 230 may emit white light, forexample that is perceived as white light by the eye. In someembodiments, the white light may be visible light with a spectral powerdistribution the chromaticity of which is close to the blackbody locusin the CIE 1931 xy or similar color space. In some embodiments, whitelight has a color temperature in the range of about 2000 K to about10,000 K. The emission wavelength, full width at half maximum (FWHM) ofthe emitted light or radiation or other optical characteristics of LEEs230 may not be all the same and are not a limitation of the presentinvention.

Substrate 265 may include or consist essentially of a semicrystalline oramorphous material, e.g., polyethylene naphthalate (PEN), polyethyleneterephthalate (PET), polycarbonate, polyethersulfone, polyester,polyimide, polyethylene, fiberglass, FR4, metal core printed circuitboard, (MCPCB), and/or paper. Substrate 265 may include multiple layers,e.g., a deformable layer over a rigid layer, for example, asemicrystalline or amorphous material, e.g., PEN, PET, polycarbonate,polyethersulfone, polyester, polyimide, polyethylene, and/or paperformed over a rigid substrate for example comprising, acrylic, aluminum,steel and the like. Depending upon the desired application for whichembodiments of the invention are utilized, substrate 265 may besubstantially optically transparent, translucent, or opaque. Forexample, substrate 265 may exhibit a transmittance or a reflectivitygreater than 70% for optical wavelengths ranging between approximately400 nm and approximately 700 nm. In some embodiments substrate 265 mayexhibit a transmittance or a reflectivity of greater than 70% for one ormore wavelengths emitted by LEE 230. Substrate 265 may also besubstantially insulating, and may have an electrical resistivity greaterthan approximately 100 ohm-cm, greater than approximately 1×10⁶ ohm-cm,or even greater than approximately 1×10¹⁰ ohm-cm. In some embodimentssubstrate 265 may have a thickness in the range of about 10 μm to about500 μm.

Conductive elements, e.g., power conductors 210, 220 and conductivetraces 260, may be formed via conventional deposition, photolithography,and etching processes, plating processes, lamination, lamination andpatterning, evaporation sputtering or the like or may be formed using avariety of different printing processes. For example, power conductors210, 220 and conductive traces 260 may be formed via screen printing,flexographic printing, ink-jet printing, and/or gravure printing. Powerconductors 210, 220 and conductive traces 260 may include or consistessentially of a conductive material (e.g., an ink or a metal, metalfilm or other conductive materials or the like), which may include oneor more elements such as silver, gold, aluminum, chromium, copper,and/or carbon. Power conductors 210, 220 and conductive traces 260 mayhave a thickness in the range of about 50 nm to about 1000 μm. In someembodiments, the thickness of power conductors 210, 220 and conductivetraces 260 may be determined by the current to be carried thereby. Whilethe thickness of one or more of power conductors 210, 220 and conductivetraces 260 may vary, the thickness is generally substantially uniformalong the length of the trace to simplify processing. However, this isnot a limitation of the present invention, and in other embodiments thethickness and/or material of power conductors 210, 220 and conductivetraces 260 may vary. In some embodiments, all or a portion of powerconductors 210, 220 and conductive traces 260 may be covered orencapsulated. In some embodiments, a layer of material, for exampleinsulating material, may be formed over all or a portion of powerconductors 210, 220 and conductive traces 260. Such a material mayinclude, e.g., a sheet of material such as used for substrate 265, aprinted layer, for example using screen, ink jet, stencil or otherprinting means, a laminated layer, or the like. Such a printed layer mayinclude, for example, an ink, a plastic and oxide, or the like. Thecovering material and/or the method by which it is applied is not alimitation of the present invention.

In one embodiment, the conductive traces 260 are formed with a gapbetween adjacent conductive traces 260, and LEEs 130 and CEs 240 areelectrically coupled to conductive traces 260 using conductive adhesive,e.g., an isotropically conductive adhesive and/or an ACA. ACAs may beutilized with or without stud bumps and embodiments of the presentinvention are not limited by the particular mode of operation of theACA. For example, the ACA may utilize a magnetic field rather thanpressure (e.g., the ZTACH ACA available from SunRay Scientific of Mt.Laurel, N.J., for which a magnetic field is applied during curing inorder to align magnetic conductive particles to form electricallyconductive “columns” in the desired conduction direction). Furthermore,various embodiments utilize one or more other electrically conductiveadhesives, e.g., isotropically conductive adhesives, non-conductiveadhesives, in addition to or instead of one or more ACAs. In otherembodiments, LEEs 230 and CEs 240 may be attached to and/or electricallycoupled to conductive traces 260 by other means, for example solder,reflow solder, wave solder, wire bonding, or the like. The method bywhich LEEs 230 and CEs 240 are attached to conductive traces 260 is nota limitation of the present invention.

CE 240 may be one component or multiple active and/or passivecomponents. In one embodiment, power conductors 210, 220 provide a DCvoltage or substantially DC voltage and CE 240 includes or consistsessentially of a resistor, e.g. a current-limiting resistor. The choiceof the resistance value may be a trade-off between a number ofparameters and characteristics that may include, e.g., efficiency andcurrent stability. In general, a larger resistance will result inreduced efficiency but greater current stability, while a smallerresistance will result in increased efficiency but reduced currentstability. Variations in the current may result from variations in theinput voltage (for example across power conductors 210, 220), variationsin forward voltage of the LEEs 230 within the string, variations in thevalue of the current-limiting resistor, variations in current that mayoccur if one or more LEEs 230 in the string become short-circuited orthe like. In the case of CE 240 including or consisting essentially of aresistor, in some embodiments CE 240 is a discrete resistor formedwithin or on conductive traces 260, such as a chip resistor, a bare-dieresistor or surface mount device (SMD) resistor.

As discussed above, in embodiments where CE 240 includes or consistsessentially of a resistor, there may be trade-offs between efficiencyand current stability. While such trade-offs may be acceptable incertain products, other products may require relatively better currentstability at higher efficiencies, and in these cases CE 240 may includeor consist essentially of multiple components or a circuit element, asdiscussed above. In some embodiments CE 240 includes or consistsessentially of a field-effect transistor (FET) and a resistor. Inanother embodiment CE 240 includes or consists essentially of twobipolar junction transistors (BJTs) and two resistors.

In general, the efficiency and current stability increase with thenumber of components, as does the cost. In some embodiments where a CE240 includes or consists essentially of multiple components, thecomponents may be in discrete form (i.e., each component individuallyelectrically coupled to conductive traces 260) or in hybrid form (wheremultiple separate components are mounted on a submount, which is thenelectrically coupled to conductive traces 260), or in monolithic form(where multiple components are integrated on a semiconductor chip, forexample a silicon-based or other semiconductor-based integratedcircuit). In some embodiments, CEs 240 may be in bare-die form, while inother embodiments CEs 240 may be packaged or potted or the like. In someembodiments, a CE 240 may include or consist essentially of a bare-dieintegrated circuit. In some embodiments, the integrated circuit includesor consists essentially of multiple active and/or passive devices thatare fabricated on a common semiconductor substrate.

In other embodiments, power conductors 210, 220 may provide AC power, orpower modulated at different frequencies and in these embodiments CEs240 may be selected accordingly or may be omitted. In one embodiment,power conductors 210, 220 may provide a standard line voltage, forexample about 120 VAC or about 240 VAC or about 277 VAC, for example atabout 50 Hz or about 60 Hz. In some embodiments, CEs 240 may accommodatea plurality of input types, and thus be so-called “universal” CEs 240,while in other embodiments different CEs 240 may be required fordifferent input types. The actual component or components of CEs 240 arenot limiting to this invention; however, in preferred embodiments ofthis invention, the positioning of CEs 240 does not disrupt the LEEpitch. In another embodiment of this invention, the positioning of CEs240 is independent of LEE pitch. As discussed herein, CEs 240 and LEEs230 may be electrically coupled to conductive traces 260 using a varietyof means, for example solder, conductive adhesive or ACA; however, themethod of electrical coupling of CEs 140 and LEEs 230 is not alimitation of the present invention.

The terms and expressions employed herein are used as terms andexpressions of description and not of limitation, and there is nointention, in the use of such terms and expressions, of excluding anyequivalents of the features shown and described or portions thereof. Inaddition, having described certain embodiments of the invention, it willbe apparent to those of ordinary skill in the art that other embodimentsincorporating the concepts disclosed herein may be used withoutdeparting from the spirit and scope of the invention. Accordingly, thedescribed embodiments are to be considered in all respects as onlyillustrative and not restrictive.

What is claimed is:
 1. A lighting system comprising: a first light panelcomprising: a first substrate, first and second spaced-apart powerconductors disposed on the first substrate, a plurality of firstlight-emitting elements disposed on the first substrate and electricallyconnected to the first and second power conductors, a first snapconnector electrically connected to the first power conductor, and asecond snap connector electrically connected to the second powerconductor; and a second light panel comprising: a second substrate,third and fourth spaced-apart power conductors disposed on the secondsubstrate, a plurality of second light-emitting elements disposed on thesecond substrate and electrically connected to the third and fourthpower conductors, a third snap connector electrically connected to thethird power conductor, and a fourth snap connector electricallyconnected to the fourth power conductor, wherein (i) the first snapconnector is configured for connection to the third snap connector,thereby electrically coupling the first power conductor to the thirdpower conductor, and (ii) the second snap connector is configured forconnection to the fourth snap connector, thereby electrically couplingthe second power conductor to the fourth power conductor.
 2. Thelighting system of claim 1, wherein the third and fourth snap connectorsare disposed on one or more tabs extending from the second substrate. 3.(canceled)
 4. The lighting system of claim 1, wherein the first lightpanel comprises: a fifth snap connector electrically connected to thefirst power conductor; and a sixth snap connector electrically connectedto the second power conductor.
 5. The lighting system of claim 4,wherein the fifth and sixth snap connectors are disposed on one or moretabs extending from the first substrate.
 6. The lighting system of claim1, wherein the second light panel comprises: a fifth snap connectorelectrically connected to the third power conductor; and a sixth snapconnector electrically connected to the fourth power conductor. 7.(canceled)
 8. The lighting system of claim 6, further comprising a powerdistribution bus comprising: first and second power distribution lines;a seventh snap connector electrically connected to the first powerdistribution line; and an eighth snap connector electrically connectedto the second power distribution line.
 9. The lighting system of claim8, wherein (i) the seventh snap connector is configured for connectionto the fifth snap connector, thereby electrically coupling the thirdpower conductor to the first power distribution line, and (ii) theeighth snap connector is configured for connection to the sixth snapconnector, thereby electrically coupling the fourth power conductor tothe second power distribution line.
 10. The lighting system of claim 8,further comprising: a first jumper comprising (i) a first jumperconnector configured for connection to the fifth snap connector and (ii)a second jumper connector configured for connection to the seventh snapconnector, thereby electrically coupling the third power conductor tothe first power distribution line, and a second jumper comprising (i) athird jumper connector configured for connection to the sixth snapconnector and (ii) a fourth jumper connector configured for connectionto the eighth snap connector, thereby electrically coupling the fourthpower conductor to the second power distribution line.
 11. The lightingsystem of claim 1, wherein at least one of the first, second, third, orfourth snap connectors comprises at least one of (i) a pin connector or(ii) at least a portion of a 9V battery connector.
 12. (canceled) 13.The lighting system of claim 1, wherein, when (i) the first snapconnector is connected to the third snap connector and (ii) the secondsnap connector is connected to the fourth snap connector, over the firstand second substrates, the first and second light-emitting elements arespaced apart at a constant pitch, the pitch being maintained between thefirst and second substrates.
 14. The lighting system of claim 1,wherein: the first substrate comprises a plurality of first conductivetraces thereon, the plurality of first light-emitting elements arespaced apart and interconnected, via the plurality of first conductivetraces, into one or more first light-emitting strings, and each firstlight-emitting string has (i) a first end electrically connected to thefirst power conductor and (ii) a second end electrically connected tothe second power conductor.
 15. The lighting system of claim 14, furthercomprising one or more first control elements each configured to controlcurrent to one or more of the first light-emitting strings, wherein (i)the one or more first control elements are disposed on at least one ofthe first substrate or the second substrate, and (ii) the one or morefirst control elements are each electrically coupled to at least onefirst light-emitting string. 16.-17. (canceled)
 18. The lighting systemof claim 14, wherein the first substrate is separable, via a cutspanning the first and second power conductors and not crossing a firstlight-emitting string, into two partial substrates each comprising (i)one or more first light-emitting strings, and (ii) portions of the firstand second power conductors configured to supply power to and therebyilluminate the one or more first light-emitting strings of the partialsubstrate.
 19. The lighting system of claim 14, wherein: along eachfirst light-emitting string, a first pitch at which the firstlight-emitting elements are spaced is substantially constant, the one ormore first light-emitting strings comprise a plurality of firstlight-emitting strings, over the first substrate, the firstlight-emitting elements are spaced apart at the first pitch, the firstpitch being maintained between first light-emitting elements ofdifferent ones of the first light-emitting strings, and when (i) thefirst snap connector is connected to the third snap connector and (ii)the second snap connector is connected to the fourth snap connector,over the first and second substrates, the first and secondlight-emitting elements are spaced apart at the first pitch, the firstpitch being maintained between the first and second substrates. 20.-21.(canceled)
 22. The lighting system of claim 1, further comprising athird light panel comprising: a third substrate, fifth and sixthspaced-apart power conductors disposed on the third substrate, aplurality of third light-emitting elements disposed on the thirdsubstrate and electrically connected to the fifth and sixth powerconductors, a fifth snap connector electrically connected to the fifthpower conductor, and a sixth snap connector electrically connected tothe sixth power conductor; and a fourth light panel comprising: a fourthsubstrate, seventh and eighth spaced-apart power conductors disposed onthe fourth substrate, a plurality of fourth light-emitting elementsdisposed on the fourth substrate and electrically connected to theseventh and eighth power conductors, a seventh snap connectorelectrically connected to the seventh power conductor, and an eighthsnap connector electrically connected to the eighth power conductor,wherein (i) the seventh snap connector is configured for connection tothe fifth snap connector, thereby electrically coupling the fifth powerconductor to the eighth power conductor, and (ii) the eighth snapconnector is configured for connection to the sixth snap connector,thereby electrically coupling the sixth power conductor to the eighthpower conductor.
 23. The lighting system of claim 22, wherein, when (i)the first snap connector is connected to the third snap connector, (ii)the second snap connector is connected to the fourth snap connector,(iii) the fifth snap connector is connected to the seventh snapconnector, (iv) the sixth snap connector is connected to the eighth snapconnector, (v) the first light panel is disposed adjacent to the thirdlight panel, and (vi) the second light panel is disposed adjacent to thefourth light panel, over the first, second, third, and fourth substratesthe first, second, third, and fourth light-emitting elements are spacedapart at a constant pitch, the pitch being maintained among the first,second, third, and fourth substrates.
 24. The lighting system of claim1, wherein the first power conductor is disposed proximate a first edgeof the first substrate.
 25. The lighting system of claim 24, wherein thefirst edge is folded to thereby increase an effective width of the firstpower conductor. 26.-27. (canceled)
 28. The lighting system of claim 1,further comprising (i) a first frame element disposed proximate a firstedge of the first substrate, and (ii) a second frame element disposedproximate a second edge of the first substrate, the second edge beingopposite the first edge, wherein (a) the first power conductor isdisposed proximate the first edge of the first substrate, and (b) thesecond power conductor is disposed proximate the second edge of thefirst substrate.
 29. (canceled)
 30. The lighting system of claim 28,wherein the first frame element (i) comprises a first electricallyconductive element, and (ii) is configured to electrically couple thefirst electrically conductive element to the first power conductor,thereby decreasing an effective electrical resistivity of the firstpower conductor; and the second frame element (i) comprises a secondelectrically conductive element, and (ii) is configured to electricallycouple the second electrically conductive element to the second powerconductor, thereby decreasing an effective electrical resistivity of thesecond power conductor.
 31. The lighting system of claim 1, furthercomprising a first frame element disposed at least partially on thefirst substrate. 32.-34. (canceled)
 35. The lighting system of claim 31,wherein (i) the first frame element comprises a first electricallyconductive element, (ii) the first power conductor comprises a pluralityof electrically discontinuous sections, and (iii) the first electricallyconductive element is configured to electrically connect at least twoelectrically discontinuous sections of the first power conductor. 36.The lighting system of claim 31, wherein the first frame element isflexible.
 37. The lighting system of claim 31, wherein the first frameelement is positionable, whereby the first frame element maintains adeformed configuration in the absence of a deforming force. 38.-48.(canceled)
 49. The lighting system of claim 1, wherein the first lightpanel has a thickness in the range of 0.25 mm to 25 mm.
 50. (canceled)51. The lighting system of claim 1, wherein the first light-emittingelements (i) comprise light-emitting diodes and (ii) emit substantiallywhite light.
 52. The lighting system of claim 1, wherein at least one ofthe first substrate or the second substrate is flexible.
 53. (canceled)54. The lighting system of claim 1, further comprising an optic disposedover at least the first light panel.
 55. The lighting system of claim54, wherein the optic comprises at least one of a lens, a diffuser, arefractive optic, a reflective optic, a Fresnel optic, a fabric, atranslucent material panel, a graphic panel, or a membrane.
 56. Thelighting system of claim 54, wherein a collective thickness of the firstlight panel and the optic is less than 500 mm. 57.-103. (canceled)